Remove catalog configurations from "kitodo_opac.xml"

[solth]

Since catalog configurations are now maintained using the new class ImportConfiguration introduced in #5038, the corresponding <catalog> entries in the main OPAC config file kitodo_opac.xml should be removed to reflect this change and to avoid confusion.

Note: the catalog configurations from the corresponding test configuration file kitodo_opac.xml should not be removed because it will be used for testing the upcoming CatalogConfigurationImporter (see #5224)

[BartChris]

By the way: The kitodo_opac.xml file seems to be necessary for creating a process. Will this be the case in the future as well or is the goal to completely remove the xml file for end users as it is intended for the kitodo_projects.xml (see #3777)