Updates referral fee types

[Rotorsoft]

Link to Issue

Closes: #10951

Description of Changes

• Changes numeric types from float to decimal(78,0) per standard
• Avoids conversions in the backend
• Fixes queries to convert from decimal to js number

Other Considerations

• UI should do the conversion

[rbennettcw]

Agreed with all said.

Another perspective on this (since I just spent a week working on fractional vote weight support in UI): the client should always receive WEI in string representation.

The backend should either pass to client as a string, or (if calculations are required), parse as BigInt then pass to client as string. That way, no precision is lost during deserialization.

The problem with double precision in the query is that it parses the value as Number (float) on the backend, which immediately loses precision.

JS floats lose precision after ~16 decimals at first, then the bigger the number gets, the more precision is lost in the decimals. WEI numbers can get pretty big (1 million ERC20 is usually 10^24 WEI), so it's a real issue now that we render fractional vote weights in the UI.