As a bridge/SDK user, I want to be able to use `permit` in order to not spend gas on approval txs.

[rhlsthrm]

Problem

What problem are we solving and why does it matter, ser? Our bridge tokens and many ERC20 tokens support permit for doing approvals: https://eips.ethereum.org/EIPS/eip-2612

We can implement this in the SDK and UI to greatly increase UX.

Proposed Solution

Thoughts on solution design. We should do to solve this problem.

• [ ] Create SDK function to generate permit sig.
• [ ] Use function in UI.

Acceptance Criteria

From an end tester and/or user perspective, the below criteria must be met to consider this done:

• [ ] UI uses permit for all tokens where it's possible.

[rhlsthrm]

@LayneHaber we need to change the BridgeFacet in order to take in permit sigs into xcall.