un-OOP the repo

[twoeths]

refer to @spiral-ladder comment #28 (review)

note that once we migrate to TreeView, all apis changes so need to coordinate with that effort

[spiral-ladder]

For more context (aside from the linked comment), I think my main observations are the following:

1. we should avoid getters and setters as much as possible to have a minimal API surface - less code has to change when a new upgrade comes around. For retrieving and manipulating data, we can simply rely on the underlying data structures' methods or the language itself.
2. Rename all getXYZ() functions that do more than just grabbing some data to something more appropriate. I can't find a link off the top of my head atm, but I remember seeing some getters do more than just simply 'get', which is problematic because it hides implementation details (the assumption is a getter would not do more than just 'get'ing). We should use unambiguous terms under such circumstances, for example computeXYZ or calculateXFromY.
3. Beyond avoiding getters/setters, we can also avoid naming things starting with get..., such as getPendingDeposits() (for example). Instead, we can just name it pendingDeposits() for brevity. This point is slightly weaker but I'm more in preference of shorter function names if it does not harm readability/clarity.