[STATS] Update stats architecture

[bragov4ik]

Main goal: allow more complex relations between charts

Main changes overview:

• flexible framework for data retrieval, processing, and storage
• flexible data dependencies with synchronized and efficient updates
• config reorganization and changes (see migration in config files folder for more)

Tech debt mitigated:

• order parameter in config changed to list; overrideable with env
• compilation without test-utils fix (tests can be run w/o the feature)
• remove duplication of configs (in runtime)
• deprecate toml config
• more accurate metrics collection (exclude mutex waiting)
• fix fill logic when to in request is None
• update some dependencies versions

Collateral changes:

• querying get_chart_data (now get_line_chart_data) without fill_missing_dates now returns data only within range according to missing date policy (for FillPrevious the first data point is moved from outside the range, if needed) (previously it could add a point before the range)

[sevenzing]

lets update README.md: ENVs and Config section