Validate specialty workloads

[check_map_tags.py](https://github.com/aws-samples/map20-tag-conformance-pack/blob/main/src/check_map_tags.py) should validate specialty workloads with corresponding specialty tag values.

The [MAP 2.0 Included Services List](https://s3-us-west-2.amazonaws.com/map-2.0-customer-documentation/included-services/MAP_Included_Services_List.pdf) shows some services (e.g. EC2) that get the generic `mig` tag value prefix. But depending upon the MAP Agreement terms, some services (e.g. RDS) should have the specialty `comm` tag value prefix for additional discount or credit. There are also specialty tag value prefixes for Oracle and SAP workloads - see [Tagging key combinations](https://s3.us-west-2.amazonaws.com/map-2.0-customer-documentation/html/AWSMapDocs/setting-up.html) for details.

A single customer account might have resources with several different tag value prefixes, though they would all have the same `map-migrated` tag key and the same [MPE ID](https://s3.us-west-2.amazonaws.com/map-2.0-customer-documentation/html/AWSMapDocs/mpe-length.html) as the tag value suffix. The current script accepts only one `tagValue` (e.g. `migA1B2C3D4E5`), and evaluates resources with any other map-migrated tag value (e.g. `commA1B2C3D4E5`) as NON_COMPLIANT.

The Conformance Pack should evaluate resources with any supported tag value prefix, and a syntactically valid MPE ID tag value suffix, as COMPLIANT. Even better, it should evaluate resources with the generic `mig` prefix but eligible for specialty tags as SUB_OPTIMALLY_COMPLIANT.