[P4-Apps] Revised metadata semantics yang module for INT v2

[Spiegel, Mickey]

New pull request is at https://github.com/p4lang/p4-applications/pull/91.

 

This will be discussed at the meeting on Monday.

 

Revise metadata semantics yang module for INT v2

• Rename p4-dtel-metadata-semantics.yang to p4-int-metadata-semantics.yang
• Align with strategy to call all aspects and variants part of INT
• Replace per metadata field groupings with generic grouping that
  can be used for metadata semantics details of all fields
• Add identity statements for each baseline metadata field
• Add identity statements for three common domain specific fields
• flow_id
• sequence_number
• mac_address
• Move leafs that apply to specific metadata fields to the generic
  grouping, conditioning the leafs using "when" statements
• Move node-id to generic grouping, conditioning this leaf
  when the metadata field is node_id
• Remove grouping for identifiers since this is moved to generic per
  metadata field groupings
• Add grouping for domain specific metadata details including
• size in 4-byte words
• INT-MX properties as defined in INT 2.1
• Add nested groupings for domain specific ids, along with bit
  position and identity reference for each domain specific metadata
  field associated with each domain