lqt(dex): setup volume trackers

[erwanor]

Describe your changes

This PR:

• expose a component level api LqtRead
• define two new DEX state key modules: lqt::v1::lp and lqt::v1::pair
• implements a position_manager::volume_tracker
• stubs out the inner position manager entrypoint, deferring implementation to later

Volume definition

We track the outflow of staking tokens from the position. This means that an attacker controlled asset must commit to a staking token inventory for at least a full block execution.

State key modeling

The lookup index maps an epoch index and a position id to a cumulative volume tally.

The full sorted index orders position ids by cumulative volume (keyed to the epoch).

Issue ticket number and link

Part of #5015

Checklist before requesting a review

• I have added guiding text to explain how a reviewer should test these changes.
  N/A

• If this code contains consensus-breaking changes, I have added the "consensus-breaking" label. Otherwise, I declare my belief that there are not consensus-breaking changes, for the following reason:

  LQT branch

[cronokirby]

Suggested changes:

• we should go ahead and stream out the volume as well, since we'll need it for correctly allocating rewards.

Suggested refactors:

• use u16 for epochs,
• rely on existing Position::reserves_for method to get the reserves for the staking token, and potentially removing the change for trading_pair.rs,
• restrict the possible changes to the volume to just adding to the tally.

[cronokirby]

Ok, let's get this merged!