Filter and normalise json output for golden test runs

[dkcumming]

This PR adds functionality to filter and normalise the json output when comparing output to the golden tests. Some cases when we want to normalise output:

1. "NormalSym" mangled function names will have a hash following 17h that will change when the compiler version changes.

<         "NormalSym": "_ZN3std2rt19lang_start_internal17h3166ab4c34d1da61E"
---
>         "NormalSym": "_ZN3std2rt19lang_start_internal17h51b943990c0e2c96E"
                                                        ^----can ignore---^

2. "symbol_name" mangled function names will have a hash following 17h that will change when the compiler version changes.

<       "symbol_name": "_ZN4core3ops8function6FnOnce9call_once17h40ba616aaa505a69E"
---
>       "symbol_name": "_ZN4core3ops8function6FnOnce9call_once17hd98db8d17b807164E"

[jberthold]

LGTM
Have to check what happened to the test workflow...