Search ext: misc cleanup & fixes

[colemanw]

Overview

• Fixes white on white button text by adding btn-default class
• Fixes missing field names in the bulk-update action
• Decouples searchActions from the main search controller
• Ensures APIv4 returns both title & titlePlural to fix sorting & a display issue in Search UI
• Misc cleanup

Before

After

Comments

The decoupling is in preparation for work on search displays, but doesn't hurt to have it in 5.31.

[civibot]

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[eileenmcnaughton]

@colemanw OK - I think this is fine for the rc - the button part is a regression & the changes are all within the search code itself which is only just going into beta so a bit less rigidity is OK.

As I mentioned in gitlab I think there is a join regression :-(

[eileenmcnaughton]

I think https://lab.civicrm.org/dev/core/-/issues/2109 is closable when this is merged