Research which instrumentation API to use to implement bridge - AST or PHP obs. API

[intuibase]

Open questions: Performance:

• is PHP Observability API caching decision between requests (AST does it once and then it is cached by Opcache)

Feature:

• are we able to check is class "implements"

Stability:

• AST must be tested by us
• OBS is official API maintained by PHP community

With AST we're able to support PHP 7.4