Add search applications API to imports and generated docs

[JoshMock]

Apparently we have to manually add new API namespaces to client.py and the sphinx API doc for them to be fully accessible to end users.

For #2253

[JoshMock]

I checked the clients-ci test output and verified that none of the integration test failures were related to this change.

[szabosteve]

@pquentin @ezimuel @picandocodigo Would either of you mind taking a look at this PR and approve, please? Thank you in advance!

[pquentin]

This looks good, thanks!

(We can discuss the unrelated run-black.py changes after merging.)

[JoshMock]

@pquentin btw the run-black.py change was just a tweak I noticed to make it more resilient by switching to a more machine-readable format. my laptop's default sensors output included some false positives in the old regex.

[github-actions]

The backport to 8.10 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-8.10 8.10
# Navigate to the new working tree
cd .worktrees/backport-8.10
# Create a new branch
git switch --create backport-2269-to-8.10
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 aebebea1e3dcde116c24f90bafab412d15e15a9a
# Push it to GitHub
git push --set-upstream origin backport-2269-to-8.10
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.10

Then, create a pull request where the base branch is 8.10 and the compare/head branch is backport-2269-to-8.10.