Corrected the v2_api? helper method

* Checks case sensitivity of '/v2'
* Checks that the '/v2' is in the start of the path
* Backfilled tests

Signed-off-by: Eric Malm <emalm@pivotallabs.com>
Remove hooks for model controller delete and add model deletion job

* refactored model controlled delete to add do_delete helper
* find_guid_and_validate_access now takes the model to find
* cleaned up service instances and app controller's overrides of delete

[#60026682]

Signed-off-by: Eric Malm <emalm@pivotallabs.com>
Model Controller #delete returns async job info

[#60026682]

Signed-off-by: Eric Malm <emalm@pivotallabs.com>