Add linter rule for hard-coded outputs

[shenglol]

Summary

• Add no-hardcoded-outputs linter rule to flag literal output values intended as constants
• Add quick fix that creates an exported variable and removes the hard-coded output
• Register the rule in config schema/resources and add focused unit tests

Fixes #18985

Validation

• dotnet test src/Bicep.Core.UnitTests/Bicep.Core.UnitTests.csproj --filter FullyQualifiedName~NoHardcodedOutputsRuleTests --no-restore

Microsoft Reviewers: Open in CodeFlow

[github-actions]

Test this change out locally with the following install scripts (Action run 28811227701)

VSCode

• Mac/Linux

  bash <(curl -Ls https://aka.ms/bicep/nightly-vsix.sh) --run-id 28811227701

• Windows

  iex "& { $(irm https://aka.ms/bicep/nightly-vsix.ps1) } -RunId 28811227701"

Azure CLI

• Mac/Linux

  bash <(curl -Ls https://aka.ms/bicep/nightly-cli.sh) --run-id 28811227701

• Windows

  iex "& { $(irm https://aka.ms/bicep/nightly-cli.ps1) } -RunId 28811227701"