Tempo: Fix TraceQL autocomplete issues (#60058)

[CrypticSignal]

This PR improves autocomplete when using the TraceQL query editor. More specifically, situations where the autocomplete values are not sufficiently filtered (#60058).

[grafanabot]

Hello @CrypticSignal!
Backport pull requests need to be either:

• Pull requests which address bugs,
• Urgent fixes which need product approval, in order to get merged,
• Docs changes.

Please, if the current pull request addresses a bug fix, label it with the type/bug label.
If it already has the product approval, please add the product-approved label. For docs changes, please add the type/docs label.
If none of the above applies, please consider removing the backport label and target the next major/minor release.
Thanks!

[grafanabot]

The backport to v9.3.x 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 branch
git switch --create backport-60125-to-v9.3.x origin/v9.3.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x 583aafbbd84ccebfa765bfac65b839fc4d33b995
# Push it to GitHub
git push --set-upstream origin backport-60125-to-v9.3.x
git switch main
# Remove the local backport branch
git branch -D backport-60125-to-v9.3.x

Then, create a pull request where the base branch is v9.3.x and the compare/head branch is backport-60125-to-v9.3.x.