feat(neon_rich_text): Init

[provokateurin]

Prerequisite for #2647.
Just moved everything to it's own package and refactored the code and tests a bit to be easier to work with.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 28.89%. Comparing base (6796ce8) to head (0a3aa4c).
Report is 11 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2682      +/-   ##
==========================================
+ Coverage   28.85%   28.89%   +0.03%     
==========================================
  Files         372      373       +1     
  Lines      136624   136622       -2     
==========================================
+ Hits        39424    39475      +51     
+ Misses      97200    97147      -53     

Flag	Coverage Δ		*Carryforward flag
account_repository	98.47% <ø> (ø)
cookie_store	99.48% <ø> (ø)		Carriedforward from 117d7a1
dashboard_app	96.05% <ø> (ø)
dynamite	31.05% <ø> (ø)		Carriedforward from 117d7a1
dynamite_end_to_end_test	61.69% <ø> (ø)		Carriedforward from 117d7a1
dynamite_runtime	85.40% <ø> (ø)		Carriedforward from 117d7a1
interceptor_http_client	97.18% <ø> (ø)		Carriedforward from 117d7a1
neon_dashboard	96.05% <ø> (ø)		Carriedforward from 117d7a1
neon_framework	59.25% <ø> (-2.19%)	⬇️
neon_http_client	93.61% <ø> (ø)		Carriedforward from 117d7a1
neon_notifications	100.00% <ø> (ø)		Carriedforward from 117d7a1
neon_rich_text	100.00% <100.00%> (?)
neon_storage	94.66% <ø> (ø)		Carriedforward from 117d7a1
neon_talk	99.45% <ø> (ø)		Carriedforward from 117d7a1
nextcloud	24.33% <ø> (+0.05%)	⬆️	Carriedforward from 117d7a1
notifications_app	97.43% <ø> (ø)
notifications_push_repository	98.11% <ø> (ø)
sort_box	90.90% <ø> (ø)		Carriedforward from 117d7a1
talk_app	99.00% <ø> (-0.01%)	⬇️

*This pull request uses carry forward flags. Click here to find out more.

Files with missing lines	Coverage Δ
...neon_rich_text/lib/src/rich_objects/deck_card.dart	100.00% <ø> (ø)
.../neon_rich_text/lib/src/rich_objects/fallback.dart	100.00% <ø> (ø)
...ages/neon_rich_text/lib/src/rich_objects/file.dart	100.00% <ø> (ø)
...s/neon_rich_text/lib/src/rich_objects/mention.dart	100.00% <ø> (ø)
...n_rich_text/lib/src/rich_objects/rich_objects.dart	100.00% <100.00%> (ø)
...ork/packages/neon_rich_text/lib/src/rich_text.dart	100.00% <ø> (ø)
...otifications_app/lib/src/widgets/notification.dart	95.74% <ø> (ø)
...ork/packages/talk_app/lib/src/widgets/message.dart	98.80% <ø> (ø)

... and 5 files with indirect coverage changes

[Leptopoda]

This was a needed cleanup. Thanks a lot.

I just have some structuring questions.