[Cashtab] Improve CreateTokenForm component and add integration tests

Summary:
Depends on D15207

CreateTokenForm takes some pointless props. Remove them. Update logic in CreateToken holder component to only render CreateTokenForm if balance condition is met.

Add integration tests for expected behavior. Delete legacy snapshot test as new integration tests already cover this.

This diff removes all snapshots from Cashtab.

Test Plan: npm test

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D15208