Adding syntax highlighting for terraform / hcl

What does this MR do?

This MR adds syntax highlighting for terraform / hcl

Monaco-editor already supports it but it seems that we can not upgrade to latest version with the current test setup

See !43058 (closed)

and also https://github.com/microsoft/monaco-languages/blob/master/src/hcl/hcl.ts

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done