Misleading second error if using `=` for a property value rather than `:`

**Is your feature request related to a problem? Please describe.**
Consider the following bicep. Whilst this is wrong bicep, it is increadibly easy to write if you're familiar with other programming languages which use `=` rather than `:`, and have a brain fart.
```bicep
var foo = {
name = 'value${deployment().name}'
}
```

Whilst the first error is correct, the second error could is a bit misleading, and is just a consequence of the parser getting confused


**Describe the solution you'd like**
Could the parser's error handling better handle this error such that the second error doesn't get reported?

Start by reproducing the reported Bicep snippet and inspect the parser diagnostics it produces. The work is done when the incorrect second error is no longer reported while the valid first error remains.

Written by the indexing model from the issue text.