Reference properties within the same resource (i.e 'this')

**Is your feature request related to a problem? Please describe.**
There are times where I need to reference properties within a resource I am creating. Currently it is not possible to reference these properties forcing me to create variables/parameters to contain the information that needs to be shared.

Current

**Describe the solution you'd like**
Be able to reference properties within the same resource.

Here is an example of a syntax. The actual syntax my vary best on what is best for the team/community.

** Other info **
Similar to #1470, but expand it beyond resource id, location, and name to other properties.

The issue names no files, tests, or entry points. Start by reviewing the resource-reference behavior discussed in #1470 and the surrounding Bicep design, then define the supported syntax and semantics for referencing other properties in the same resource; done means the agreed scenarios work without intermediate variables.

Written by the indexing model from the issue text.