post https://api.tec.tjrsgon.com/tmi-api/v1/markets/roles/grant/tx
Build a transaction for granting a role to a user account towards the specified onchain token market.
The populated transaction will grant the specified role to the target user account on the specified token market.
The populated transaction will be signed and sent by the market owner/admin account, or by a user account having the
corresponding role management ability.