Add backtrace to forge

[ksew1]

Closes #2468

Introduced changes

• Forge will display backtrace for contracts in format similar to rust

Checklist

• Linked relevant issue
• Updated relevant documentation
• Added relevant tests
• Performed self-review of the code
• Added changes to CHANGELOG.md

[ksew1]

This was inspired by Rust backtrace, but there are a couple of things to note in terms of user experience.

When Forge encounters an error, it suggests enabling a backtrace for more context:

Failure data:
    (0x454E545259504F494E545F4E4F545F464F554E44 ('ENTRYPOINT_NOT_FOUND'), 0x454E545259504F494E545F4641494C4544 ('ENTRYPOINT_FAILED'))

note: run with `SNFORGE_BACKTRACE=1` environment variable to display a backtrace

Enabling backtrace provides a call stack:

Failure data:
    (0x454E545259504F494E545F4E4F545F464F554E44 ('ENTRYPOINT_NOT_FOUND'), 0x454E545259504F494E545F4641494C4544 ('ENTRYPOINT_FAILED'))

error occurred in contract 'InnerContract' at pc: '72'
possible stack backtrace:
   0: InnerContract::inner_call
       at src/lib.cairo:47:9
   1: InnerContract::inner
       at src/lib.cairo:38:13
   2: InnerContract::__wrapper__inner
       at src/lib.cairo:37:9

[...]

Tests: 0 passed, 1 failed, 0 skipped

However ...

• If functions are not inlined, only the line causing the failure is shown, without the functions that call them:

  0: InnerContract::inner_call
       at src/lib.cairo:47:9
  

  The Cairo compiler inlines aggressively, so often you will get the whole call stack from the entry point, which is really helpful when debugging. But in the worst-case scenario, you only get the last line. I was thinking because of that should we always display the last line, but I believe the whole call stack is really helpful.

• Currently, the VM does not halt immediately upon encountering a panic and do bubbles it up, so backtraces may display only the contract's entry point.

In terms of UX, if you prefer something different, we can easily change this as the backend will probably stay the same.

[ksew1]

Also, I will add documentation in a separate PR to avoid making this one any bigger.

[franciszekjob]

Good job 👌