fix: create default openid client scope

[UnicornChance]

Description

There is no current openid default client scope that is necessary for mattermost integration, and probably others eventually as well.

Tested against local keycloak ( uds-core ).

Related Issue

Fixes #38

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Test, docs, adr added or updated as needed
• Contributor Guide Steps(https://github.com/defenseunicorns/uds-template-capability/blob/main/CONTRIBUTING.md#submitting-a-pull-request) followed