Chore: Remove unused Blaze templates after message rewrite

[ggazzo]

body -> refactor

emojiPicker -> refactor

authorize -> refactor
oauth404 -> refactor

CodeMirror -> refactor

inputAutocomplete
_autocompleteContainer ->inputAutocomplete
_noMatch -> inputAutocomplete
loading -> inputAutocomplete
roomSearch -> inputAutocomplete -> roomPicker setting
    roomSearchEmpty


username -> refactor
customFieldsForm -> username, refactor

messagePopupSlashCommandPreview -> refactor

RocketSearch -> globalSearch remove or refactor
    DefaultSuggestionItemTemplate
    DefaultSearchResultTemplate
    ExternalFrameContainer

Proposed changes (including videos or screenshots)

Issue(s)

Steps to test or reproduce

Further comments

[codecov]

Codecov Report

Merging #28025 (20f9258) into develop (88f7024) will increase coverage by 1.25%.
The diff coverage is 51.61%.

@@             Coverage Diff             @@
##           develop   #28025      +/-   ##
===========================================
+ Coverage    42.24%   43.49%   +1.25%     
===========================================
  Files          812      795      -17     
  Lines        16052    15371     -681     
  Branches      2072     2066       -6     
===========================================
- Hits          6781     6686      -95     
+ Misses        8991     8401     -590     
- Partials       280      284       +4     

Flag	Coverage Δ
e2e	43.49% <51.61%> (+1.25%)	⬆️

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[aleksandernsilva]

I don't have the context for all the changes, but codewise lgtm.