Rename provider -> extension in many places

[anthony-c-martin]

Microsoft Reviewers: Open in CodeFlow

[github-actions]

Test this change out locally with the following install scripts (Action run 10512011211)

VSCode

• Mac/Linux

  bash <(curl -Ls https://aka.ms/bicep/nightly-vsix.sh) --run-id 10512011211

• Windows

  iex "& { $(irm https://aka.ms/bicep/nightly-vsix.ps1) } -RunId 10512011211"

Azure CLI

• Mac/Linux

  bash <(curl -Ls https://aka.ms/bicep/nightly-cli.sh) --run-id 10512011211

• Windows

  iex "& { $(irm https://aka.ms/bicep/nightly-cli.ps1) } -RunId 10512011211"

[github-actions]

Dotnet Test Results

    72 files   -     36      72 suites   - 36   22m 44s ⏱️ - 10m 47s
11 044 tests  -     20  11 044 ✅  -     19  0 💤 ±0  0 ❌  - 1 
25 864 runs   - 12 928  25 864 ✅  - 12 927  0 💤 ±0  0 ❌  - 1 

Results for commit ee366f0. ± Comparison against base commit 68f9bca.

♻️ This comment has been updated with latest results.

[shenglol]

Thanks for doing this!