chore: Refactor & Improve Livechat Widget API

[MartinSchoeler]

TODO

• [x] Refactor Hooks.js and Widget.js to Typescript
• [ ] Improve Error handling in API calls (today we basically check almost nothing)
• [x] Create tests for the Livechat API (Probably will be done in another PR, with the old API as base so we are sure nothing was broken)
• [ ] Review Existing documentation on the API

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: 654cb1973a2b366fc0d8f3c90718dc3552469fd1

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@rocket.chat/livechat	Minor

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 54.57%. Comparing base (cd5cbe2) to head (654cb19). Report is 9 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #30924      +/-   ##
===========================================
+ Coverage    54.49%   54.57%   +0.07%     
===========================================
  Files         2270     2276       +6     
  Lines        50095    50148      +53     
  Branches     10219    10275      +56     
===========================================
+ Hits         27300    27368      +68     
- Misses       20322    20334      +12     
+ Partials      2473     2446      -27     

Flag	Coverage Δ
unit	76.47% <ø> (ø)

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