feat: add sonic spec

[oren-lava]

Description

Closes: #XXXX

Added Sonic (previously Fantom) spec. This will be a separate spec until Fantom is completely not supported

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Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• read the contribution guide
• included the correct type prefix in the PR title, you can find examples of the prefixes below:
• confirmed ! in the type prefix if API or client breaking change
• targeted the main branch
• provided a link to the relevant issue or specification
• reviewed "Files changed" and left comments if necessary
• included the necessary unit and integration tests
• updated the relevant documentation or specification, including comments for documenting Go code
• confirmed all CI checks have passed

Reviewers Checklist

All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed all author checklist items have been addressed
• reviewed state machine logic, API design and naming, documentation is accurate, tests and test coverage

[github-actions]

Test Results

2 519 tests  ±0   2 518 ✅ ±0   25m 18s ⏱️ - 2m 1s
  124 suites ±0       1 💤 ±0 
    7 files   ±0       0 ❌ ±0 

Results for commit 362c54e. ± Comparison against base commit 5e4b420.