IBX-8019: Replaced LocationService::loadLocationChildren usages with SearchService::findLocations

[webhdx]

Question	Answer
JIRA issue	IBX-8019
Type	improvement
Target Ibexa DXP version	v3.3
BC breaks	no
Doc needed	no

Replaced usage of LocationService::loadLocationChildren in favor of SearchService::findLocations which operates much faster.

I wanted to keep changes as concise as possible, however found out that affected tests LocationEventSubscriber and TrashEventSubscriber did not checked run any checks against calling EventNotificationService::sendNotification which is what is the most important part of the subscribers.

Related PRs:

• IBX-8019: Added performance consideration notice to LocationService::loadLocationChildren ezplatform-kernel#407
• IBX-8019: Replaced LocationService::loadLocationChildren use with SearchService ezplatform-admin-ui#2119
• IBX-8019: Replaced LocationService::loadLocationChildren usages with SearchService::findLocations #114

Checklist:

• Provided PR description.
• Tested the solution manually.
• Provided automated test coverage.
• Checked that target branch is set correctly (master for features, the oldest supported for bugs).
• Ran PHP CS Fixer for new PHP code (use $ composer fix-cs).
• Asked for a review (ping @ezsystems/php-dev-team).

[webhdx]

@konradoboza Fixed

[ciastektk]

@webhdx, CI is red

[webhdx]

@ciastektk Fixed, forgot to push updated PHPStan baseline 🤦

[tomaszszopinski]

QA approved on IbexaDXP exp 3.3.37.