[IMPROVE] Expand the feature set of the new message rendering (#25970)

<!-- This is a pull request template, you do not need to uncomment or remove the comments, they won't show up in the PR text. -->

<!-- Your Pull Request name should start with one of the following tags
  [NEW] For new features
  [IMPROVE] For an improvement (performance or little improvements) in existing features
  [FIX] For bug fixes that affect the end-user
  [BREAK] For pull requests including breaking changes
  Chore: For small tasks
  Doc: For documentation
-->

<!-- Checklist!!! If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code. 
  - I have read the Contributing Guide - https://github.com/RocketChat/Rocket.Chat/blob/develop/.github/CONTRIBUTING.md#contributing-to-rocketchat doc
  - I have signed the CLA - https://cla-assistant.io/RocketChat/Rocket.Chat
  - Lint and unit tests pass locally with my changes
  - I have added tests that prove my fix is effective or that my feature works (if applicable)
  - I have added necessary documentation (if applicable)
  - Any dependent changes have been merged and published in downstream modules
-->

## Proposed changes (including videos or screenshots)
<!-- CHANGELOG -->
<!--
  Describe the big picture of your changes here to communicate to the maintainers why we should accept this pull request.
  If it fixes a bug or resolves a feature request, be sure to link to that issue below.
  This description will appear in the release notes if we accept the contribution.
-->
- Everything inside a new package (`@rocket.chat/gazzodown`);
- KaTeX support;
- Highlighted Words support;
- Emoji rendering expanded;
- Code rendering fixed
<!-- END CHANGELOG -->

## Issue(s)
<!-- Link the issues being closed by or related to this PR. For example, you can use #594 if this PR closes issue number 594 -->

## Steps to test or reproduce
<!-- Mention how you would reproduce the bug if not mentioned on the issue page already. Also mention which screens are going to have the changes if applicable -->

## Further comments
<!-- If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc... -->

_templates/package/new/package.json.ejs.t

@@ -18,7 +18,7 @@ to: packages/<%= name %>/package.json
 		"lint:fix": "eslint --ext .js,.jsx,.ts,.tsx . --fix",
 		"jest": "jest",
 		"build": "rm -rf dist && tsc -p tsconfig.json",
-		"dev": "tsc -p --watch --preserveWatchOutput tsconfig.json"
+		"dev": "tsc -p tsconfig.json --watch --preserveWatchOutput"
 	},
 	"main": "./dist/index.js",
 	"typings": "./dist/index.d.ts",

apps/meteor/app/theme/client/imports/general/base_old.css

@@ -2934,6 +2934,8 @@
 .rc-old .highlight-text {
 	padding: 2px;
 
+	color: inherit;
+
 	border-radius: 15px;
 	background-color: var(--selection-background);
 }