Add ServiceDashboardClientManager#errors

This change means the ServiceDashboardClientManager no longer needs to
mutate the state of the CatalogService objects. We also introduced a
ValidationErrors class and a ValidationErrorsFormatter, which will
replace Catalog#error_text.

[#62008174]
Persist the requires value from a catalog for a service. [#66387038]

- github issue #172
- when a broker catalog had a service that provided a requires
list, it was not being persisted to the database.
Do not change app package_state to PENDING upon creation/deletion of service_bindings [fixes #66888284]
Use ValidationErrors in catalog, services and plans

Also change catalog and service validations, so that validating a
catalog service adds the errors from its plans to the catalog errors.
The same is true for adding service errors to the catalog's errors.

Also, remove logic on Catalog for generating human-readable validation
error message. It now delegates to the ValidationErrorsFormatter

[#62008174]
Move ValidationErrorsFormatter to ServiceBrokers ns

[#62008174]
Simplify access control classes [#66904450]

Signed-off-by: Phan Le <ple@pivotallabs.com>
Http interaction with service brokers does not verify ssl certs if the cc is configured with skip_cert_verify: true [finishes #66520656]
VCAP::CloudController::ServiceBroker -> ServiceBrokers

This avoids the requirement that the ServiceBroker model be loaded
before we load any files in the VCAP::CloudController::ServiceBroker
namespace

[#62008174]
Remove #error_text method from Catalog

Now using ValidationErrorsFormatter instead

[#62008174]
User cannot modify applications in a suspended organization

[Finishes #66904450] [Finishes #66904482]

Signed-off-by: Phan Le <ple@pivotallabs.com>
Quote conversion

Signed-off-by: Phan Le <ple@pivotallabs.com>
Users cannot create domains in suspended organizations

[Finishes #66904542]

Signed-off-by: Phan Le <ple@pivotallabs.com>
Add memoization to the base authorization class for performance

Signed-off-by: Phan Le <ple@pivotallabs.com>
More readable access rules

[#66904542]

Signed-off-by: Phan Le <ple@pivotallabs.com>
Cannot create space in suspended organization

[Finishes #66904542]

Signed-off-by: Phan Le <ple@pivotallabs.com>