Improve "My keys" section

[sosnovsky]

let's improve My keys section in FlowCrypt Settings:

• keys should be ordered from the newest to the oldest
• expired keys should have decreased opacity (~0.7) to better differentiate with active keys
• let's convert this list to table with columns, as currently rows are not same-aligned:

User ID	Creation	Fingerprint	Status
user@example.com	November 24, 2025	C3A6 5E46 7B54 77DF 3C4C 9790 4D22 B3CA 5B32 FF66	active
...	...	...	...

Maybe some other possible improvements?