[processor/transform] Replace ParserCollection and add initial support for context inference

[edmocosta]

Description

This PR is part of #29017, and a split from #36888. It changes the transformprocessor, adding the initial support for expressing statement's context via path names.

Change log:

• Replaced the custom ParserCollection implementation with the new ottl.ParserCollection.
• When the context configuration key is set (current mode), it relies on the parser collection and statements rewrite utility to prepend the configured context value on the statements paths, making it backward compatible and not requiring users to change their existing configurations.
• If the context configuration key is empty, it requires all statements's paths to have a valid context prefix, and relies on the context inferrer utility to choose the right parser.
• Added initial support for passing the cache value to parser's TransformContext.
• collector/consumer interfaces are not implemented anymore.

Examples:

log_statements:
  # Expressing contexts via path names (no context key value)
  - statements:
     - set(log.attributes["name"], "replaced")

   # Existing format
  - context: log
    statements:
      - set(attributes["name"], "replaced")

Link to tracking issue

#29017,

Testing

Unit tests

[TylerHelmuth]

Needs a changelog and if we can make it so that the existing user's use of cache is unaffected that I believe it can be an enhancement instead of breaking.

[TylerHelmuth]

@evan-bradley please review. I'll merge on Friday unless there are objections or you merge it first.