Fix report deletion through API

[LightOfHeaven1994]

Delete report through API doesn't work. Also before deleting report itself we need to delete ReportFile otherwise DB is going to complain.
Delete report issue I observe:

[2024-04-08 12:52:46,979] ERROR in app: Exception on /api/report/4170cf45-9d0e-4da8-8d10-464ffcc29386 [DELETE]
Traceback (most recent call last):
File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 2529, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 1825, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/local/lib/python3.9/site-packages/flask_cors/extension.py", line 176, in wrapped_function
return cors_after_request(app.make_response(f(*args, **kwargs)))
File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 1823, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/local/lib/python3.9/site-packages/flask/app.py", line 1799, in dispatch_request
return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
File "/usr/local/lib/python3.9/site-packages/connexion/decorators/decorator.py", line 68, in wrapper
response = function(request)
File "/usr/local/lib/python3.9/site-packages/connexion/security/security_handler_factory.py", line 388, in wrapper
return function(request)
File "/usr/local/lib/python3.9/site-packages/connexion/decorators/uri_parsing.py", line 149, in wrapper
response = function(request)
File "/usr/local/lib/python3.9/site-packages/connexion/decorators/validation.py", line 399, in wrapper
return function(request)
File "/usr/local/lib/python3.9/site-packages/connexion/decorators/parameter.py", line 120, in wrapper
return function(**kwargs)
File "/app/ibutsu_server/util/uuid.py", line 28, in validate
return function(**kwargs)
TypeError: delete_report() got an unexpected keyword argument 'user'

Tested locally, works as expected