feat: add GMP native token handler adapter

[nmlinaric]

Description

Adds adapter for native token trasnfers via GMP.

Related Issue Or Context

Closes: #231

How Has This Been Tested? Testing details.

unit and e2e tests

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation

Checklist:

• I have commented my code, particularly in hard-to-understand areas.
• I have ensured that all acceptance criteria (or expected behavior) from issue are met
• I have updated the documentation locally and in chainbridge-docs.
• I have added tests to cover my changes.
• I have ensured that all the checks are passing and green, I've signed the CLA bot

[lastperson]

If native currencies are of the same value between the origin and destination, then perhaps we should have a single adapter implementation deployed on both chains to facilitate movement in both directions?

[mpetrun5]

The implementation is OK, though I would consider adapter implementations be part of another repo with them.
sygma-solidity IMO should only be for core solidity stuff.

[nmlinaric]

Closing this as for the time being it will not be used in production