first pass: --sample

[MichelleArk]

resolves #
docs dbt-labs/docs.getdbt.com/#

Problem

Solution

Checklist

• I have read the contributing guide and understand what's expected of me
• 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
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the contributing guide.

[codecov]

Codecov Report

Merging #8337 (a912b25) into main (556b404) will decrease coverage by 21.10%.
Report is 2 commits behind head on main.
The diff coverage is 61.53%.

@@             Coverage Diff             @@
##             main    #8337       +/-   ##
===========================================
- Coverage   86.23%   65.14%   -21.10%     
===========================================
  Files         174      174               
  Lines       25518    25527        +9     
===========================================
- Hits        22005    16629     -5376     
- Misses       3513     8898     +5385     

Files Changed	Coverage Δ
core/dbt/context/providers.py	65.99% <0.00%> (-22.67%)	⬇️
core/dbt/adapters/base/relation.py	61.50% <71.42%> (-32.14%)	⬇️
core/dbt/cli/main.py	86.25% <100.00%> (-12.44%)	⬇️
core/dbt/cli/params.py	97.67% <100.00%> (-2.33%)	⬇️

... and 113 files with indirect coverage changes

[mwstanleyft]

Adapters should be provided the ability to override the SQL used for the sample operation. LIMIT clauses do not change BigQuery's billing behaviour, so a better option would be to use the TABLESAMPLE syntax on that database.