Update react-native example to expo@46

[hrougier]

I did this in the premium task context before seeing someone else submitted another PR :/

This PR contains:

• Update to latest expo@46
• Update of configuration files and dependencies based on the latest create-expo-app templates (.gitignore, app.json, icons, splashscreen image...)
• Usage of expo-splash-screen while database is being initialized
• Usage of .expo-shared for assets (npx expo-optimize)
• usage of text-encoding-polyfill to avoid app crashing (rxdb uses the TextEncoder class from DOM)
• Support for hot reloading (avoid an rxdb error where the db got reinitialized on each hot reloading)
• Removed no longer needed dependencies from package.json
• Some code refactoring to improve readability (src folder and some others)
• Update screenshot with latest iPhone simulator
• added a .nvmrc file pointing to v16 because expo-cli does not support v18

Example is now fully working on a simulator.

Describe the problem you have without this PR

• Example is not working (expo@43 not longer supported by ExpoGo) and crashes for various reasons enumerated above)

Some remaining issues

• Git sees some moved files as deleted/recreated (sorry!)
• Console errors during jest testing because setState is being called after it finished its test (it finishes before the splashscreen is hidden)
• Testing the app render after the splashscreen is hidden cannot be done because of a segmentation fault likely due to this issue with dynamic imports, below is the crash report when you try to do so

PID 86695 received SIGSEGV for address: 0x0
0 segfault-handler.node 0x0000000108cb134c _ZL16segfault_handleriP9__siginfoPv + 288
1 libsystem_platform.dylib 0x00000001ac4354c4 _sigtramp + 56
2 node 0x0000000104215a88 _ZN4node6loaderL23ImportModuleDynamicallyEN2v85LocalINS1_7ContextEEENS2_INS1_14ScriptOrModuleEEENS2_INS1_6StringEEENS2_INS1_10FixedArrayEEE + 236
3 node 0x00000001044bfabc _ZN2v88internal7Isolate38RunHostImportModuleDynamicallyCallbackENS0_6HandleINS0_6ScriptEEENS2_INS0_6ObjectEEENS0_11MaybeHandleIS5_EE + 248
4 node 0x0000000104835254 _ZN2v88internal25Runtime_DynamicImportCallEiPmPNS0_7IsolateE + 396
5 node 0x0000000104b44e44 Builtins_CEntry_Return1_DontSaveFPRegs_ArgvInRegister_NoBuiltinExit + 100
6 node 0x0000000104bd3218 Builtins_CallRuntimeHandler + 88
7 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
8 node 0x0000000104b0a02c Builtins_GeneratorPrototypeNext + 140
9 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
10 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
11 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
12 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
13 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
14 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
15 node 0x0000000104ad5858 construct_stub_create_deopt_addr + 344
16 node 0x0000000104bd3bb0 Builtins_ConstructHandler + 656
17 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
18 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
19 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
20 node 0x0000000104b0a02c Builtins_GeneratorPrototypeNext + 140
21 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
22 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
23 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
24 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
25 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
26 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
27 node 0x0000000104ad5858 construct_stub_create_deopt_addr + 344
28 node 0x0000000104bd3bb0 Builtins_ConstructHandler + 656
29 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
30 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248
31 node 0x0000000104ad8858 Builtins_InterpreterEntryTrampoline + 248

[hrougier]

So I've fixed the App.test.js the best I could 😅 (found the await new Promise(setImmediate) trick on several stackoverflows looking for how to test an async useEffect).

Let me know if there are things to improve/not ok.

Not sure if the memory adapter is a good choice as the database does not persist (not a real usecase).
Otherwise it seems like a good example for people wanting to start using rxdb in expo with up to date templates and best pratices like integrating with the splashscreen.

Maybe the need for text-encoding-polyfill is unfortunate as TextEncoder is used only once in rxdb and it's the only thing that makes rxdb not compatible with native environments.

[pubkey]

I accientially merged code from #3903 which is why there is the memory storage used.
I reverted this now.

We need to use the PouchDB storage because only that contains a non-premium sqlite based adapter and has the asyncstorage as alternative.

also we need either the couchdb or the rxdb-replication running.

Using the TextEncoder for hashing reduced the hash runtime by about a third. So I do not want to remove that. But maybe we can use a workarround instead of a polyfill. Because the textencoder does the same as calling charCodeAt over an array of chars.

[pubkey]

Closing this in favor of #3903