CORE-5010 Added /filesystem/move-contents endpoint.

Added a filesystem.move/move-contents function that fetches all paths in a source directory and moves them to a destination directory.
Added a filesystem.validators/validate-num-paths-under-folder function, used by the new move-contents function, that will throw an ERR_TOO_MANY_PATHS exception if the total number of paths under a folder is more than the util.config/fs-max-paths-in-request value.
CORE-5010 Added /filesystem/move-contents docs.
Added ERR_TOO_MANY_PATHS to /filesystem/move docs.
CORE-5010 Added move-contents source validation.

Added source directory validation to the /filesystem/move-contents endpoint.
Fixed move-contents docs and added it to endpoint index.
CORE-5011 Added /filesystem/delete-contents endpoint.

Added a services.filesystem.trash/delete-contents function that fetches all paths in a directory and deletes them.
Added ERR_TOO_MANY_PATHS to /filesystem/delete docs.
CORE-5028 Added /filesystem/restore-all endpoint.

Added a services.filesystem.trash/restore-all function that restores all items in the user's trash.
Added ERR_TOO_MANY_PATHS to /filesystem/delete docs.
Merge remote-tracking branch 'remotes/origin/dev'