[Data Explorer] Clean out angular contents in Discover

[ananzh]

Issues Resolved

#4459

Blocked by
Step 1: #4432
Step 2: #4458

[codecov]

Codecov Report

Merging #4468 (1368051) into feature/data-explorer (6e0a855) will increase coverage by 0.10%.
The diff coverage is 100.00%.

@@                    Coverage Diff                    @@
##           feature/data-explorer    #4468      +/-   ##
=========================================================
+ Coverage                  66.47%   66.57%   +0.10%     
=========================================================
  Files                       3280     3278       -2     
  Lines                      62700    62645      -55     
  Branches                    9766     9759       -7     
=========================================================
+ Hits                       41679    41708      +29     
+ Misses                     18648    18570      -78     
+ Partials                    2373     2367       -6     

Flag	Coverage Δ
Linux	66.52% <100.00%> (?)
Windows	66.52% <100.00%> (+0.05%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
...on/components/doc_viewer/doc_viewer_render_tab.tsx	80.00% <ø> (ø)
...ation/components/sidebar/discover_field_search.tsx	90.56% <ø> (+3.29%)	⬆️
...tion/components/sidebar/discover_index_pattern.tsx	87.50% <ø> (ø)
...mponents/skip_bottom_button/skip_bottom_button.tsx	100.00% <ø> (ø)
...blic/application/components/table/table_helper.tsx	100.00% <ø> (ø)
...plication/components/top_nav/open_search_panel.tsx	50.00% <ø> (ø)
...public/application/doc_views/doc_views_registry.ts	0.00% <ø> (ø)
.../discover/public/opensearch_dashboards_services.ts	58.82% <ø> (+1.68%)	⬆️
src/plugins/discover/public/plugin.ts	0.00% <ø> (-1.37%)	⬇️
...over/public/application/components/table/table.tsx	84.61% <100.00%> (ø)

... and 7 files with indirect coverage changes