Implement T-CONV and T-REPLACE-RX entry placeholders

[droidmonkey]

• Closes #7293
• Move existing T-CONV and T-REPLACE-RX code from AutoType to Entry. Replumb AutoType to use the entry functions.
• Improve placeholder code in various place

Testing strategy

Added unit tests

Type of change

• ✅ New feature (change that adds functionality)

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 97.80220% with 2 lines in your changes missing coverage. Please review.

Project coverage is 63.87%. Comparing base (2fc24be) to head (1dd1039). Report is 3 commits behind head on develop.

Files with missing lines	Patch %	Lines
src/core/Entry.cpp	97.59%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #11453 +/- ## =========================================== + Coverage 63.84% 63.87% +0.03% =========================================== Files 362 362 Lines 38115 38134 +19 =========================================== + Hits 24334 24358 +24 + Misses 13781 13776 -5 ```

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