Remove data-code-raw for pre blocks

[BartoszGrajdek]

After we changed the syntax for codeFence we found a bug where it was possible to add a room mention inside of it. This PR prevents that from happening & removes data-code-raw which is not necessary after all of our changes.

Fixed Issues

$ GH_LINK

Tests

1. What unit/integration tests cover your change? What autoQA tests cover your change?
   All of the tests that were edited
2. What tests did you perform that validates your changed worked?
   I checked if there were any new errors inside of react-native-live-markdown library and inside of E/App (which was not necessary since these changes don't affect it).

QA

1. What does QA need to do to validate your changes?
   Don't know actually, this is a clean-up rather than a feature
2. What areas to they need to test for regressions?
   I've added some regression test to check for room mentions inside of codeFence

[BartoszGrajdek]

cc @dangrous since he was responsible for reviewing the previous PR and has context on what's happening here 👀

[youssef-lr]

LGTM

[github-actions]

🚀Published to npm in v2.0.9

[dangrous]

Much cleaner! Do we have a test in there that checks that urls inside

s work properly? Other than that I think this is good to go.