What does this PR do?

This PR adds support for using the allowedvalues metadata exposed by CloudStack API discovery to provide direct value autocompletion in CloudMonkey.

Changes

• Add AllowedValues to the APIArg struct.
• Parse the allowedvalues field from the API discovery response in UpdateCache().
• Use AllowedValues during autocompletion before falling back to the existing findAutocompleteAPI() heuristic.

Behavior

When a parameter exposes allowedvalues through API discovery, CloudMonkey now suggests those values directly.

For example:

create snapshotpolicy intervaltype=

Pressing TAB now suggests values such as:

HOURLY
DAILY
WEEKLY
MONTHLY

Parameters that do not expose allowedvalues continue to use the existing autocomplete behavior, so there is no behavioral change for parameters without this metadata.

Related

Builds on the API discovery changes introduced in apache/cloudstack#13543.