[Bug] Allow meta in semantic model entities

[siljamardla]

Is this a new bug in metricflow?

• I believe this is a new bug in metricflow
• I have searched the existing issues, and I could not find an existing issue for this bug

Current Behavior

It's a dbt standard that any configurations also take the meta key. In case of semantic model entities, this does not work.
For example

semantic_models:
  - name: dim_city
    description: City dimension
    model: ref('dim_city')
    entities:
      - name: city_id
        type: primary
        meta:
          state: live
      - name: country_id
        type: foreign

will result in the following error:

Parsing Error
  Invalid semantic_models config given in ... - at path ['entities'][0]: Additional properties are not allowed ('meta' was unexpected)

Expected Behavior

Meta should be supported to enable the governance that dbt usually enables. Sample use cases might include adding business knowledge about the entity, ownership, domains etc.

Steps To Reproduce

Try to add a meta key to an existing semantic model.

Relevant log output

Environment

- OS:
- Python:
- dbt:
- metricflow:

Which database are you using?

No response

Additional Context

No response