[Cashtab] Temp disable token send for 9-decimal tokens

Summary: An intermittent issue with bch-api can cause invalid token transactions for SLPA utxos having 9 decimal places

Test Plan: npm start ; confirm sending is disabled for 9-decimal SLPA tokens and warning msg present

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D9391