Validation of types in GlueSchema2.1

[enolfc]

Short Description of the issue

Some fields have defined types (specially closed enums) that we should check that the values we publish are within the allowed values. See for example QualityLevel_t, which populates the GLUE2ServiceQualityLevel and is basically taken from the the configuration file without any validation

Environment

N/A

• Operating System:
• python version:
• OpenStack version:

Steps to reproduce

N/A

Logs, stacktrace, or other symptoms

N/A

Summary of proposed changes

Add validation to the fields

[gwarf]

First review done by @enolfc.
Final refiew be done by @gwarf