[Uber EPIC] Update HSCS to support advanced HTS features (airdrops & Metadata)

### Problem

HSCS has partial support for HIP 904 as it's missing the advanced Hedera flow in which a delegated smart contracts can issue HIP 904 functions.

Additionally, HIPs 6464, 657, 765 are not yet support by HSCS due to blockers in system contract versioning.

### Solution

- [ ] Add support for admin key delegated smart contracts to support HIP 904 function
- [ ] Implement 1028 with HTS system contract support for HIPs 6464, 657, 765

### Alternatives

_No response_

Start by mapping the HSCS implementation and its system-contract versioning path, then read HIP 904, HIP 1028, HIP 6464, HIP 657, and HIP 765. Break the work into the delegated smart-contract flow and the versioning changes, with completion defined as support for the listed HIP features and appropriate validation for each.

Written by the indexing model from the issue text.