[Cashtab] [BCH deprecation] Pt 2/2 - Deprecate BCH.SLP.TokenType1.generateSendOpReturn

Summary:
T2730

Depends on D12412

This diff switches the send OP_RETURN script logic to the newly created local function.

Test Plan:
npm test
npm start
send an existing token, ensure successful broadcast and validate explorer for token destination and token/XEC change outputs
send a newly created token and verify as above
send a full balance of a token and verify no token change outputs

Reviewers: bytesofman, #bitcoin_abc

Reviewed By: bytesofman, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D12418