[feature] getting rid of default encoding - changing it to utf-8

[skryzh]

Brief summary of the change made

Getting rid of default (global) encoding for systems like Windows (cp1251, cp66, etc.).
Inspired by "Fluent Python" (Book by Luciano Ramalho)

Manually checked on environments (constraints/)

• Env: Ubuntu 22.04.4 LTS; Python 3.10.12:

  • dbt140.txt
  • dbt150.txt
  • dbt160.txt
  • dbt170.txt
  • dbt180.txt

• Env: Windows 10 10.0.19044; Python 3.10.10:

  • dbt150-winpy.txt
  • dbt180-winpy.txt

Are there any other side effects of this change that we should be aware of?

This changes affect core, so we need to be careful with review.

Pull Request checklist

• Please confirm you have completed any of the necessary steps below.

• Included test cases to demonstrate any code changes, which may be one or more of the following:

  • .yml rule test cases in test/fixtures/rules/std_rule_cases.
  • .sql/.yml parser test cases in test/fixtures/dialects (note YML files can be auto generated with tox -e generate-fixture-yml).
  • Full autofix test cases in test/fixtures/linter/autofix.
  • Other.

• Added appropriate documentation for the change.

• Created GitHub issues for any relevant followup/future enhancements if appropriate.

[github-actions]

Coverage Results ✅

Name    Stmts   Miss  Cover   Missing
-------------------------------------
TOTAL   18357      0   100%

237 files skipped due to complete coverage.

[coveralls]

Pull Request Test Coverage Report for Build 11052786786

Details

• 11 of 11 (100.0%) changed or added relevant lines in 8 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 99.985%

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Totals
Change from base Build 11033644630:	0.0%
Covered Lines:	20405
Relevant Lines:	20408

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💛 - Coveralls