Add "High Precision" option for users to enable in settings.

[aaroncox]

Opening an issue based on the discussion here: https://greymass.slack.com/archives/C02EN8NRTL4/p1731628914858109?thread_ts=1731616250.789369&cid=C02EN8NRTL4

This idea came up around USD values, and whether their precision should be 2 or 4.

The raw data we get for USD prices comes at a precision of 4, but the currency in reality has a precision of 2. It might be strange for new people to see USD with 4 decimal places, and an argument could be made that by default we render it with 2 so its a more familiar currency value.

However, more advanced users may want to see that precision - and if we default to a precision of 2, there should be an option for these advanced users to see that precision.

[deansallinen]

Kinda already started this - I used the advanced mode toggle to switch to four digit decimals on usd. Advanced mode and "High Precision" should be separate though, I think.