Make a partial ordering struct

[ValarDragon]

A problem we face right now is that BeginBlock, EndBlock, and Upgrades require specification of a total ordering of modules in an upgrade.

This causes a number of problems:

• It is hard to understand where to put a new module
• Listing every module obscures the important before/after relations
• A lot of code bloat

Ideally we should just specify the relevant partial orderings, and it can then derive a satisfying total ordering.

e.g.

BeginBlockOrdering := osmoutils.NewPartialOrdering(AllModuleNames)
BeginBlockOrdering.AfterRelation(Staking.ModuleName, Bank.ModuleName) // Staking upgrade has to come after bank
BeginBlockOrdering.BeforeRelation(Auth.ModuleName, Bank.ModuleName) // Auth has to come before bank
// can also have a First or Last method if we want

App.SetBeginBlockOrdering(BeginBlockOrdering.TotalOrdering())

(We then use this to replace

osmosis/app/modules.go

Line 188 in 44099c5

func orderBeginBlockers() []string {

)

This should be relatively simple to add, by wrapping a topological sort library, e.g. https://github.com/stevenle/topsort . See topological sorting / partial ordering -> total ordering posts for more details: https://en.wikipedia.org/wiki/Topological_sorting#Relation_to_partial_orders

[ValarDragon]

Closed by #1335, not sure why this wasn't automatically closed