Merge PR #32288 into master

* refs/pull/32288/head:
	test_cephfs_shell: remove test_every_shell_cmd_at_invocation
	test_cephfs_shell: catch specific exception instead of catching all
	cephfs-shell: set return value before exiting
	test_cephfs_shell: re-arrange TestCephFSShell's methods
	cephfs-shell: re-arrange code under __main__
	test_cephfs_shell: add new test for shell cmd at invocation
	cephfs-shell: launch shell only if there are no args following

Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>
Reviewed-by: Varsha Rao <varao@redhat.com>