refactor(frontend): extract dataset settings into Settings tab

[rbelavadi]

What changes were proposed in this PR?

Extracted the dataset settings/admin functionality on the dataset detail page into a dedicated Settings tab, alongside existing content (now under a Data Card tab). Part of the parent tab-based layout refactor (#6394).

Visibility toggle, downloadable toggle, and description editor moved from the header's gear-icon popover into the new Settings tab. The gear icon and popover are removed.
Added dataset rename (input + Save), calling the existing DatasetService.updateDatasetName() and reusing the name-sanitization logic already used in the dataset version creator.
Added dataset delete, calling the existing DatasetService.deleteDatasets() with the same nz-popconfirm confirmation pattern used on the Datasets list page; redirects to the list on success.

Before: settings were scattered, visibility/downloadable behind a gear icon, description editable only in the header, rename/delete only reachable from the Datasets list page.

After: all dataset settings are consolidated in one Settings tab on the detail page itself.

Any related issues, documentation, discussions?

Closes #6395

How was this PR tested?

Added 7 unit tests to dataset-detail.component.spec.ts covering the two new methods (onSaveDatasetName, onDeleteDataset): name sanitization, success/error paths, and navigation on delete. The relocated toggles/description editor already had existing test coverage prior to this PR, so no new tests were needed there. 66/66 tests passing (59 pre-existing, 7 new).

Also manually tested on UI, since the relocated functionality itself is unchanged behavior:

• Renamed a dataset; confirmed persistence and correct sanitization of invalid characters.
• Edited and saved the description; confirmed it reflects on the Datasets list page.
• Toggled visibility and downloadable; confirmed state persists and header badges update accordingly.
• Deleted a test dataset; confirmed confirmation prompt, successful deletion, and redirect to the Datasets list with the dataset removed.
• Confirmed the Data Card tab (file browser, version history, uploads) is unaffected.

Was this PR authored or co-authored using generative AI tooling?

Generated-by: Claude Code (Claude Opus 4.8)

[github-actions]

Automated Reviewer Suggestions

Based on the git blame history of the changed files, we recommend the following reviewers:

• Contributors with relevant context: @kunwp1, @mengw15, @Yicong-Huang
  You can notify them by mentioning @kunwp1, @mengw15, @Yicong-Huang in a comment.

[rbelavadi]

/request-review @xuang7

[codecov-commenter]

Codecov Report

❌ Patch coverage is 69.69697% with 70 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.87%. Comparing base (49f9e2c) to head (c2d0026).

Files with missing lines	Patch %	Lines
...ser-dataset-explorer/dataset-detail.component.html	66.18%	67 Missing and 3 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6493      +/-   ##
============================================
- Coverage     78.96%   78.87%   -0.09%     
+ Complexity     3798     3765      -33     
============================================
  Files          1161     1161              
  Lines         46084    46140      +56     
  Branches       5110     5115       +5     
============================================
+ Hits          36388    36391       +3     
- Misses         8076     8135      +59     
+ Partials       1620     1614       -6     

Flag	Coverage Δ		*Carryforward flag
access-control-service	70.00% <ø> (ø)		Carriedforward from 9de1386
agent-service	76.76% <ø> (ø)		Carriedforward from 9de1386
amber	71.87% <ø> (-0.36%)	⬇️	Carriedforward from 9de1386
computing-unit-managing-service	20.49% <ø> (ø)		Carriedforward from 9de1386
config-service	66.66% <ø> (ø)		Carriedforward from 9de1386
file-service	67.21% <ø> (ø)		Carriedforward from 9de1386
frontend	82.99% <69.69%> (+0.08%)	⬆️
notebook-migration-service	78.94% <ø> (ø)		Carriedforward from 9de1386
pyamber	95.38% <ø> (ø)		Carriedforward from 9de1386
workflow-compiling-service	55.14% <ø> (ø)		Carriedforward from 9de1386

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

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[xuang7]

Generally LGTM! I left a few comments. Since we now have a new rename method, could you please update this to reuse the same logic here?

[xuang7]

LGTM! Please resolve the conflicts and update the PR description.