TCA8418 keypad interface optimisations

[Slankydudl]

Altered the 12 key multitap implementation to make it work more intuitively and contextually aware. Allowing for fairly efficient UI navigation and text entering with no additional interface, broadly mimicking a trackball when in UI and keypad in free text.

Changes

• Keypad layout starts with alpha to make entering text faster.
• Keypad defaults to a navigation keymap when not in a free text entering state (navigation retained on long press).
• Navigation keys repeatedly fire in all contexts until released.
• Reply with freetext destination defaults to last viewed message context.
• Added key to enter reply with freetext without having to naviagate.
• Added more long press key functions in free text, to quickly change dest, exit free text, or send the message.

🤝 Attestations

• I have tested that my proposed changes behave as described.
• I have tested that my proposed changes do not cause any obvious regressions on the following devices:
  • Heltec (Lora32) V3
  • LilyGo T-Deck
  • LilyGo T-Beam
  • RAK WisBlock 4631
  • Seeed Studio T-1000E tracker card
  • Other (please specify below)
  • Heltec V4
  • Heltec T114
  • Seed XIAO nRF52840 & Wio-SX1262 Kit

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[github-actions]

@Slankydudl, Welcome to Meshtastic!

Thanks for opening your first pull request. We really appreciate it.

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There's a big backlog of patches at the moment. If you have time,
please help us with some code review and testing of other PRs!

Welcome to the team 😄

[Slankydudl]

need to see how this can be merged with #7989, so far seems not to break the existing keypad implementation