Cross-agent unit testing for Azure Instrumentations

[basepi]

The Azure Instrumentations are all built around a REST API. In practice, this means there are generally large if-statement blocks that set the operation name and resource based on various pieces of the REST request. (See elastic/apm-agent-python#1316 for examples in Python)

@beniwohli pointed out that it would be useful to encode the tables in the spec into JSON such that unit tests could be constructed to ensure consistency across agents.