[DoDiODev]

Summary

When adding data scopes to a SonarQube connection (Connection → Add Data
Scope), the search box only lets you pick the matching projects one by one.
With a few hundred projects sharing a prefix this is tedious.

This PR adds an "ALL" checkbox as the first entry of the search result
list. It selects or deselects all projects matching the search term, not
only the page that is currently loaded. The feature is opt-in per plugin and
is only switched on for SonarQube.

Backend (feat(sonarqube): return total count from search-remote-scopes)

• DsRemoteApiScopeSearchHelper can now return the total number of matches
  as count in the search-remote-scopes response.
  • New function type DsSearchRemoteScopesWithCount and constructor
    NewDsRemoteApiScopeSearchHelperWithCount.
  • The existing NewDsRemoteApiScopeSearchHelper wraps its function and
    reports the total as unknown (-1). In that case count is omitted from
    the response. No other plugin changes; the response of all other
    plugins is unchanged.
  • DsRemoteApiScopeList documents the optional count field (Swagger).
• SonarQube: querySonarqubeProjects also returns paging.total from
  api/components/search_projects, and the search endpoint uses the new
  constructor.

config-ui (feat(config-ui): add "ALL" toggle to the SonarQube remote scope search)

• New optional plugin config flag dataScope.searchSelectAll, set to true
  for SonarQube only.
• The "ALL" row is rendered via renderTitle of MillerColumnsSelect, so it
  sits inside the list, before the first item, and looks like a list item.
  The built-in showSelectAll of miller-columns-select is not used: it only
  covers the already loaded items and replaces the whole selection.
• Behaviour of the checkbox:
  • Label shows the number of matches, e.g. ALL (237) (from count, or the
    list length once the whole result is loaded).
  • Tri-state: checked / indeterminate / unchecked. Scopes that already exist
    (disabled entries) are ignored.
  • If not all pages are loaded yet, a click loads the remaining pages first
    (spinner shown). With count the loop stops exactly at the last page;
    without it, it stops at the first short page. Limit: 100 pages × 100.
    If the limit is hit, a warning asks to refine the search.
  • Selection outside the current filter is always kept. Clicking again only
    removes the filtered entries.
  • If the search term changes while loading, the stale result is discarded.
• Small fixes in search-remote.tsx: results are de-duplicated when the next
  page is appended, and the memoised disabledIds is reused.
• API.scope.searchRemote: count is now typed as optional.

Question for reviewers

The new behaviour is opt-in and currently enabled for SonarQube only. Should
it become the default for all plugins with a remote search? That covers:

1. Showing the number of matches behind the checkbox (ALL (n)), and
2. Loading all pages of the search result when "ALL" is clicked, instead
   of acting only on the loaded items.

The helper extension is already generic. Each plugin would only need to
return the total from its search function (many remote APIs report it, for
example GitHub search total_count or Jira total; this would need to be
checked per plugin). Without a
total, the UI falls back to "load until a short page" and shows the count
only after everything is loaded. Plugins that use NewDsRemoteApiScopeSearchHelper
today: azuredevops_go, bamboo, bitbucket, bitbucket_server, circleci,
gh-copilot, github, gitlab, grafana_irm, incidentio, jira, pagerduty, rootly,
slack, sonarqube, tapd, teambition, tempo, testmo, trello.

If you agree, I would prefer a follow-up PR: drop the searchSelectAll flag
(or flip its default) and add count plugin by plugin. That keeps this PR
small. I'm also happy to change it here if you prefer.

Does this close any open issues?

N/A

Screenshots

Other Information

• Backwards compatible: count is only added to the response when a plugin
  reports it; existing clients ignore unknown fields.
• Tests:
  • Go: new unit tests for the helper (count present / omitted, legacy
    wrapper) and for querySonarqubeProjects (mocked ApiClient; checks
    paging.total, filter, p, ps).
  • config-ui: Vitest unit tests for the select-all helpers and component
    tests for the "ALL" row (15/15). tsc and eslint pass.
• Fork CI on the same change (golangci-lint, unit-test, e2e on MySQL,
  config-ui, license header, Grafana check; 14/14 jobs green):
  https://github.com/DoDiODev/devlake/actions/runs/40840628487