Add CLI acceptance tests for files_external occ commands

[phil-davis]

We have some UI tests for adding local storage in the admin storage settings. But we have very little tests for the files_external occ commands that create/modify/delete storages.

Add test coverage for:

• files_external:applicable [Tests-Only] Add acceptance test to remove all for local storage mount #37012 Move scenarios from cliMain/files.feature to cliLocalStorage and refactor #36707
• files_external:backends [Tests-Only] Add acceptance test to show available backends using the occ command #37035
• files_external:config [Tests-Only] Add acceptance test to manage backend config for local storage mount #37015
• files_external:create Move scenarios from cliMain/files.feature to cliLocalStorage and refactor #36707 Add cliLocalStorage test suite with first createLocalStorage.feature #36689
• files_external:delete [Tests-only] Add acceptance test to delete local storage using occ command #36756
• files_external:export [Tests only] Add acceptance test to export created mounts using occ command #36794
• files_external:import Fix files_external:export so the output can be successfully imported #37513
• files_external:list [Tests-only] Add acceptance test to list all created local storage using occ command #36754
• files_external:option [Tests-Only] Add acceptance test to manage options for local storage mount #37018
• files_external:verify [Tests-Only] Add acceptance tests to verify mount configurations using the occ command #36806

[phil-davis]

See #36689 for the first files_external:create test scenario.

[kiranparajuli589]

Adding tests for files_external:import is currently blocked due to #37054

[phil-davis]

files_external:export => files_external:import was fixed and test added in PR #37513