Better tx multi-input/output management

[Klakurka]

Currently we show the same spending tx multiple times if it has multiple inputs.

Example:
https://explorer.e.cash/tx/28b29131da9f004cd007e5d0bb887b37f6440262e22a6bf1bb33e973c58364de

Likely related to #920 because it might just be splitting them up because they're coming from different addresses.

This is less of any issue for outputs (incoming txs) IMO but might want to think about that one as well.

[Klakurka]

This would also improve the CSVs which right now list each individual input being spent instead of 1 entry for the entire tx.