perf(tags): reduce repeated query setup in hot loops

[joshtrichards]

• Resolves: #

Summary

Reduce a bit of repeated query setup and parameter binding in OC\Tags.

• bind the invariant uid and type parameters once in getTagsForObjects(); loop only updates the chunk parameter
• reuse a single relation-insert query builder in save()
• bind the invariant relation type parameter once in save(); the loop only updates objid and categoryid

TODO

• ...

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI