[WIP] Refactor spec

[photoszzt]

Description

Pull out the common pieces. Most of them are ava_unsupported function templates.

How has this been tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Document update (this change is mainly a documentation update)

Checklist:

• My code passes format and lint checks.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new warnings.
• I have tested my code with a reasonable workload.
• My code may break some other features.