Create explicit rawInputReplacement function for userMentions

[robertKozik]

Extends the implementation of userMentions to include explicit rawInputReplacement function. With this change we ensure that input string is not changed when shouldKeepRawInput flag is raised

Fixed Issues

$ Expensify/App#40414

Tests

1. What unit/integration tests cover your change? What autoQA tests cover your change?
   I"ve added unit test to catch the situation when input string contains phone number mention and shouldKeepRawInput flag is raised.

2. What tests did you perform that validates your changed worked?
   I've tested it inside react-native-live-markdown example library - with this change we no longer experience console.error described in linked issue.

QA

1. What does QA need to do to validate your changes?
   Updating expensify-common version inside parser directory of react-native-live-markdown and testing it inside it's example application
2. What areas to they need to test for regressions?
   As we are only introducing separate rawInputReplacement there should be no regressions outside of react-native-live-markdown and Composer component inside E/App

[pecanoro]

@grgia All yours

[pecanoro]

@grgia Friendly bump!

[pecanoro]

I am merging the PR since it's been 2 days so we can bump the version.