Update project load tracking for v0.20 parsing changes

[jtcohen6]

Describe the feature

Let's add fields to track_project_load so we can account for / disambiguate between:

• Whether partial parsing is enabled (we use is_partial_parse_enabled for this today)
• Total number of files in the project (we use path_count for this today)
• Number of files actually re-parsed by partial parsing (this is what path_count represents in v0.20rc1, we should keep these separate)
• Whether the experimental parser is enabled
• Number of files eligible to be parsed by experimental parser (just models today, but could be more in the future)
• Number of files actually parsed by experimental parser

https://github.com/fishtown-analytics/dbt/blob/abe8e839458d0288f76cb6950e79c77e3b1627cc/core/dbt/parser/manifest.py#L599-L617

[kwigley]

adding:

• parsed_path_count -> path_count can represent the size of the project and amount of files eligible to be parsed while parsed_path_count will be the actual amount of files parsed
• is_static_analysis_enabled -> set if flag for experimental parser is turned on
• static_analysis_path_count -> number of files eligible to be parsed by experimental parser
• static_analysis_parsed_path_count -> number of files actually parsed by experimental parser