Write lint sarif output to stdout instead of stderr

[anthony-c-martin]

• Makes bicep lint command simpler to use with sarif + output redirection (described in Export lint output to file #11960)
• Simplify the diagnostic logging logic to avoid the need to 'setup' and 'flush' the logger.

Microsoft Reviewers: Open in CodeFlow

[github-actions]

Test this change out locally with the following install scripts (Action run 7183564318)

VSCode

• Mac/Linux

  bash <(curl -Ls https://aka.ms/bicep/nightly-vsix.sh) --run-id 7183564318

• Windows

  iex "& { $(irm https://aka.ms/bicep/nightly-vsix.ps1) } -RunId 7183564318"

Azure CLI

• Mac/Linux

  bash <(curl -Ls https://aka.ms/bicep/nightly-cli.sh) --run-id 7183564318

• Windows

  iex "& { $(irm https://aka.ms/bicep/nightly-cli.ps1) } -RunId 7183564318"

[github-actions]

Test Results

     132 files  ±0       132 suites  ±0   4h 21m 40s ⏱️ - 3m 37s
10 927 tests ±0  10 927 ✔️ +3  0 💤 ±0  0 ❌  - 3 
52 631 runs  ±0  52 631 ✔️ +3  0 💤 ±0  0 ❌  - 3 

Results for commit 2447457. ± Comparison against base commit e64dd8c.

♻️ This comment has been updated with latest results.