Add script for monitoring pools for

[AndriiDiachuk]

Summary

Adds get_pool_liquidity.cdc - a read-only Cadence script that reports liquidity status for a configurable list of Uniswap V3 pools deployed on Flow EVM.

This script is consumed by the fcm-observer
monitoring service, which calls it on a periodic basis to expose Prometheus metrics
for pool health alerting.

For each pool the script performs three dry EVM calls:

1. factory.getPool(tokenA, tokenB, fee) — resolves the pool contract address
2. pool.liquidity() — checks whether there is any current in-range liquidity
3. tokenA/tokenB.balanceOf(pool) — reads actual token reserves held by the pool

Token balances are scaled to 8 decimal places (UFix64) using
FlowEVMBridgeUtils.uint256ToUFix64 with floor rounding for tokens with more than
8 decimals.

If any call fails (e.g. pool not yet deployed, RPC error), the pool entry is still
returned with balanceA=0, balanceB=0, hasLiquidity=false so the caller always
receives a complete response and metrics are never absent.

Metrics exposed by fcm-observer (context)

Metric	Description
fcm_pool_token_balance{pool, token}	Token reserve balance (UFix64 units)
fcm_pool_has_liquidity{pool}	1.0 = in-range liquidity present, 0.0 = empty

Related PR: https://github.com/onflow/fcm-observer/pull/111

[vishalchangrani]

@AndriiDiachuk can you please post sample input and output of the script?