Escape strings correctly in snippets

[anthony-c-martin]

Use the syntax factory + pretty printer to emit snippets rather than ad-hoc string formatting. This avoids having to deal with edge cases like escaping.

Closes #14578

Microsoft Reviewers: Open in CodeFlow

[github-actions]

Test this change out locally with the following install scripts (Action run 9993989999)

VSCode

• Mac/Linux

  bash <(curl -Ls https://aka.ms/bicep/nightly-vsix.sh) --run-id 9993989999

• Windows

  iex "& { $(irm https://aka.ms/bicep/nightly-vsix.ps1) } -RunId 9993989999"

Azure CLI

• Mac/Linux

  bash <(curl -Ls https://aka.ms/bicep/nightly-cli.sh) --run-id 9993989999

• Windows

  iex "& { $(irm https://aka.ms/bicep/nightly-cli.ps1) } -RunId 9993989999"

[github-actions]

Dotnet Test Results

    72 files   -     36      72 suites   - 36   24m 15s ⏱️ - 6m 57s
10 957 tests  -     18  10 957 ✅  -     18  0 💤 ±0  0 ❌ ±0 
25 810 runs   - 12 895  25 810 ✅  - 12 895  0 💤 ±0  0 ❌ ±0 

Results for commit 36dc155. ± Comparison against base commit 684e6d4.

♻️ This comment has been updated with latest results.