feat: mitigate inverse relationship problems in swaps; more tests; clean up spot price

[p0mvn]

Closes: #XXX

What is the purpose of the change

This PR is focused on truncations in the right direction as we square "square root price" in swaps.

While working on inverse relationship tests, I realized that some of the fractional residues due to intermediary math calculations are inevitable. Ref: #4998 (comment)

In swaps, what we want to guarantee is that we always round in the direction of the pool. As a result, here we introduce a method defined on the swap strategy that rounds in the desired direction based on swap strategy.

There are 2 drive-by changes here:

• Refactoring CalculateSpotPrice keeper method to use pool's spot price implementation instead of re-implementing on its own
• Adding more inverse relationship tick to price test vectors

Brief Changelog

• add math.SquareRoundUp and math.SquareRoundDown
• add SquareSqrtPrice defined on each of the swap strategies and utilizing the methods above
• add tick to price inverse relationship tests
• refactor CalculateSpotPrice

Testing and Verifying

This change is already covered by existing tests

Documentation and Release Note

• Does this pull request introduce a new feature or user-facing behavior changes? no
• Is a relevant changelog entry added to the Unreleased section in CHANGELOG.md? no
• How is the feature or change documented? not applicable

[AlpinYukseloglu]

Nice work, I really like the abstractions you set up here