Replace NoticonTextView by Vector Drawables

[maxme]

When #3856 is merged, we can remove NoticonTextView (it was a trick to use a special font for rendering vector icons) and replace them with image views (and equivalent vector drawables).

[maxme]

@theck13 is your Vectorize all the things PR fixing this one?

[theck13]

The vectorize-all-the-things pull request does not address Noticons. I created #4921 and #4925 for fixing Noticon references.

[maxme]

Perfect, thanks!

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