Explore converting bicep error codes to natural language style instead of numeric codes

For:

```
The parameter type is not valid. Please specify one of the following types: "array", "bool", "int", "object", "string".
```

Instead of code `BCP031` we could have something like `parameter-type-not-valid`

This will align with the error codes we have planned for the linter, but we need to make sure we can produce something relevant for some of the more abstract errors.

Start by reviewing Bicep's current numeric error-code definitions and the planned linter error-code conventions. Determine whether each existing error can receive a useful natural-language identifier, including abstract errors, and document the resulting naming approach and migration scope.

Written by the indexing model from the issue text.