add Capability.TableLastModifiedMetadataBatch support

[MichelleArk]

resolves ##965
docs dbt-labs/docs.getdbt.com/#

Problem

• dbt-snowflake adapter metadata-based freshness can be computed in batch by using the base adapter implementation of calculate_source_freshness_from_metadata_batch, but the capability has not yet been enabled

Solution

• enable capability + add tests (continued with pattern of individual test (not inherited) in this file)

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the dbt-snowflake contributing guide.

[MichelleArk]

The verify packages CI check is failing on Check wheel distrubutions with:

AttributeError: TableLastModifiedMetadataBatch. Did you mean: 'TableLastModifiedMetadata'?

It seems like the branch setting of batch-metadata-freshness on dbt-adapters does not propagate to that step. It should be resolved once dbt-labs/dbt-adapters#127 is merged.