Handle v2-only registration fields in v1 downgrade

[sylvesterkaczmarek]

Summary

• omit v2-only taxonomy docking metadata when translating registrations to BSI Flex 335 v1.0
• omit MOVE_TO, PATROL, and FOLLOW capability declarations because those command types do not exist in the v1 enum
• preserve supported command definitions and reconstruct their v1 name field
• add regression coverage for the two downgrade failures reported in ERROR sapient_apex_server.translator.proto_to_proto_translator: translate_v2_to_v1 failed #1

Addresses #1

Rationale

BSI Flex 335 v2.0 added extensible taxonomy docking and the MOVE_TO, PATROL, and FOLLOW command types. These have no representation in the v1 registration schema. The downgrade path currently passes them into ParseDict, which rejects the registration.

This change makes the downgrade intentionally lossy only for those v2-only registration capabilities while preserving fields that v1 can represent.

Testing

• added test_v2_registration_downgrade_omits_v2_only_taxonomy_and_commands

[sylvesterkaczmarek]

The downgrade still leaves V2-only RegionType values in registration task definitions. V2 adds REGION_TYPE_MOBILE_NODE_NO_GO_AREA and REGION_TYPE_MOBILE_NODE_GO_AREA, but V1 only defines 0–3; ParseDict(..., V1) will reject such a registration and translate_v2_to_v1() returns an empty message after catching the exception. Remove/translate those region types during downgrade and add a regression alongside the V2-only command test.