Same-T Fund functionality

**Is your feature request related to a problem? Please describe.**

Same-T Funds were introduced to Bitshares, however they're unsuported by the reference wallet.

**Describe the solution you'd like**

Construct multi-operation transactions which borrow, utilize and then repay same-t funds.

Enable users to create same-t funds from within the reference ui.

**Describe alternatives you've considered**

Use the Bitshares Astro UI - both aspects of same-t funds are fully implemented in that user interface.

**Additional context**

This functionality is going unused - if the reference wallet implemented support perhaps people would use it.

No source files, tests, or entry points are named. Start by locating the reference wallet's transaction and same-T fund handling, then compare it with the Astro UI implementation cited in the issue. Done means users can create same-T funds and complete borrow, use, and repay flows through multi-operation transactions.

Written by the indexing model from the issue text.