Use RingBuffer in ValueHistory

[wvpm]

Replaces #574

#545 added tracking balance history per country.
Also price history is tracked since #288

They used ValueHistory which is flawed in several ways:

• it has a static size so you don't know how many periods of history it has (required for UI).
• it requires filling with a single value (0 isn't practical when you need to find a min and max, since 0 could be a normal value and thus can't be used to identify empty values)
• it uses a vector instead of array despite having a compile-time constant capacity available
• it's implementation deviates from the industry standard circular buffer or ring buffer

For these reasons, it is now based on Spartans RingBuffer (#575 )