Add velocore on linea (and telos)

[NIXBNT]

This is a draft PR that provides a template to get started on integrating the new exchange Velocore.
https://docs.velocore.xyz/technical-docs

Preliminary testing has been done on a Tenderly fork on Linea and backdate_pools in functioning with correct pool data.
With the correct fetching of current pool state from backdate_pools, it correctly populates the pool data, allows curve generation and discovery of arbitrage opportunities - however CANNOT handle live events in its current state.
The partial implementation in this POC is modelled on handling of the solidly forks.
This work is concerned primarily with Velocore's volatile pools - they have separate handling for their stable (wombat) pools.

The code presented here is simply a POC and requires rewriting/testing/review.

There are a number of known outstanding issues (by no means is this comprehensive):

1. Velocore requires the use of 3 contracts Vault, Factory, Lens. The Lens contract was added to the multichain_addresses.csv under a new column ancillary_address (since the Factory falls under factory_address, and the Vault serves much of the router functionality)
   1.a. Originating from the Vault contract - "Swap" events refer to the "pool" but have a unique challenge of having a list of relevant tokens (bytes) in tokenRef and a corresponding delta change to the token amounts - these lists can have more than 2 entries! Again, note, this is a delta not the resulting reserve amount = math. This will require specific logic (see appendix 1.a.)
   1.b. Factory contract can be used to get "PoolCreated" events with the tokens provided as bytes t1, t2 (see appendix 1.b.). I was able to implement handling that supports getting the static data from the terraformer (not necessarily perfect but functional in scope).
   1.c. The Lens contract is used to retrieve pool data and appears to only provide current data (i.e. cannot retrieve previous pool states from this contract). Inside the poolData is the poolParams which contain current reserves for the pool and fee info. Pool data is LENS.queryPool(pool_address) (examples in appendix 1.c.).
   1.d. poolData -> poolParams
   WARNING - Pools can be implemented with non-standard (i.e. not 50:50) token weights - while no pools are implemented like this currently it is possible.
   The fee for each pool is in the poolParams essentially the first 64 bytes of the poolParams / 10**18
   More info on the poolParams: https://github.com/velocore/velocore-contracts/blob/4f9bbbd6e0de052725d8642e3efa4904059d44b2/src/pools/constant-product/ConstantProductPool.sol#L424
   An example of extracting info from poolParams is in appendix 1.d - this is not a suggestion for implementation just a POC.
   These methods have been used in this draft to successful get static pool data and do backdate_pools - please update as appropriate.

2. The swap interfaces matches univ2 so it should work with much of the existing infra. More info here: https://docs.velocore.xyz/technical-docs/how-to-interact-with-velocore/uniswap-compatible-interface

3. For the Event fetching to work correctly, we need to make a choice: a) fetch all pools state from pool data with multicall every iteration or b) tackle the challenges of the "Swap" event containing multiple tokens and using deltas instead of new reserves. If we choose (b) then there are many changes required that I dont have a comprehensive understanding of.

4. Added a new file velocore_event_mappings.csv that may need to be handled

5. Search TODO, in some cases it was unclear how best to access constants and so some token addresses were temporarily hardcoded - (e.g. events\pools\velocore_v2.py)

APPENDIX
1.a.

1.b.


1.c.


1.d.