[Project Tracking] Prototype and Proposal for Milestone 1 - Fully resolved registry / telemetry schema

[jsuereth]

From our OTEP plan, we have the first milestone to achieve:

Introduce a registry section with a list of fully resolved attributes, metrics, and other telemetry signals from the existing semantic convention registry. Upon implementation, the OpenTelemetry project's telemetry schema will include a registry of all standardized attributes, metrics, and signals as defined by the semantic conventions.

This is a meta issue tracking progress towards a prototype and proposal:

Tasks

• Add missing features in Telemetry Schema #10
• Add missing features in the Semantic Convention Registry resolution process #9
• Add more tests to validate the semconv registry resolution process #8
• Implement the process for resolving a Semantic Convention Registry #3