[!!!][TASK] Streamline ExtensionManagementUtility

The following functionality within this API class is marked as deprecated:
- siteRelPath()
- getExtensionKeyByPrefix()
- removeCacheFiles()
- second parameter of isLoaded()

Additionally, the following more strict rules apply now:
- addNavigationComponent() always requires an $extensionKey
- First parameter of addLLrefForTCAdescr() must not be empty
- addService() requires $serviceType and $info to be non-empty
- addPlugin() always requires an $extensionKey
- addStaticFile() throws exceptions if no extension key or path is set
- addTypoScript() expects $type to be either "setup" or "constants"

This is meant for extension developers using the current API more properly
than before.

Resolves: #82899
Releases: master
Change-Id: Ie5beddd4787da25f05f76ff37c6ec55a92257001
Reviewed-on: https://review.typo3.org/54523


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreibe...