[AAE-3405] - Optimise attach file widget UI

[arditdomi]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x")

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation
• Other... Please describe:
  Styling updates

What is the current behaviour? (You can also link to an open issue here)
https://issues.alfresco.com/jira/browse/AAE-3405

What is the new behaviour?
The attach file widget dialog size is now bigger, the search-panel UI can be expanded-collapsed and it is moved on the left

Does this PR introduce a breaking change? (check one with "x")

• Yes
• No

If this PR contains a breaking change, please describe the impact and migration path for existing applications: ...

Other information:

[codecov-io]

Codecov Report

Merging #6271 into develop will increase coverage by 1.95%.
The diff coverage is 70.00%.

@@             Coverage Diff             @@
##           develop    #6271      +/-   ##
===========================================
+ Coverage    76.31%   78.27%   +1.95%     
===========================================
  Files          863      352     -511     
  Lines        19523     9632    -9891     
  Branches      3891     1950    -1941     
===========================================
- Hits         14899     7539    -7360     
+ Misses        3461     1504    -1957     
+ Partials      1163      589     -574     

Impacted Files	Coverage Δ
...rm/services/content-cloud-node-selector.service.ts	33.33% <0.00%> (ø)
.../components/search-panel/search-panel.component.ts	80.00% <66.66%> (-20.00%)	⬇️
...-selector/content-node-selector-panel.component.ts	85.32% <80.00%> (-0.23%)	⬇️
...ontent-services/src/lib/mock/content-model.mock.ts	100.00% <100.00%> (ø)
...ore/notifications/services/notification.service.ts
lib/core/toolbar/toolbar-divider.component.ts
...ib/core/userinfo/components/user-info.component.ts
...nents/raphael/icons/raphael-icon-mule.component.ts
...nents/icons/diagram-icon-service-task.component.ts
lib/insights/src/test.ts
... and 509 more

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