[#2990] Normalize global CLI args/flags

[gshank]

resolves #2990

Description

Make global CLI arguments/flags consistent by allowing them to be set 1) as a command line argument (before subcommands), 2) as an environment variable 3) in the config part of the profile.

Checklist

• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have updated the CHANGELOG.md and added information about my change to the "dbt next" section.

[gshank]

Removed: strict, use_cache, test_new_parser.

Added command line argument before subcommands: --no-version-check, --fail-fast, --profiles_dir.

Global CLI flags: use_experimental_parser, debug, log_format, write_json, partial_parse, use_colors, send_anonymous_user_stats, no_version_checks, fail_fast, profiles_dir, printer_width.

All environment variables start with DBT_, like DBT_PROFILES_DIR.

[jtcohen6]

Really solid start! Excited to clean up our docs for this :)

[jtcohen6]

Love how organized + centralized these all are now

[gshank]

I've merged the flags with the 'args' that show up in run_results.json. I removed the 'profiles_dir' attribute from UserConfig. Switched to using flags.VERSION_CHECK instead of args. etc etc. Going to review the flags to make sure they're all actually being used and that there are tests, but hopefully functionality is done.

[nathaniel-may]

Oh wow. I didn't realize these were so all over the place. Looks like a solid improvement to me.