Add getters for immutables for LsETH and rETH

[cashd]

• Added getter functions for immutables in LsETH/rETH integrations.
• Added test for getter functions for code coverage.

[github-actions]

Hyperdrive Gas Benchmark

Benchmark suite	Current: b592328	Previous: 46c834d	Deviation	Status
addLiquidity: min	33915 gas	1546 gas	2093.7257%	🚨
addLiquidity: avg	145457 gas	67936 gas	114.1089%	🚨
addLiquidity: max	405253 gas	293159 gas	38.2366%	🚨
checkpoint: min	29232 gas	1182 gas	2373.0964%	🚨
checkpoint: avg	104066 gas	48477 gas	114.6709%	🚨
checkpoint: max	211255 gas	191559 gas	10.2819%	🚨
closeLong: min	31428 gas	1492 gas	2006.4343%	🚨
closeLong: avg	132883 gas	29374 gas	352.3831%	🚨
closeLong: max	366431 gas	152303 gas	140.5934%	🚨
closeShort: min	31349 gas	1494 gas	1998.3266%	🚨
closeShort: avg	127882 gas	33444 gas	282.3765%	🚨
closeShort: max	201614 gas	149156 gas	35.1699%	🚨
initialize: min	31283 gas	1451 gas	2055.9614%	🚨
initialize: avg	252985 gas	213962 gas	18.2383%	🚨
initialize: max	322173 gas	253953 gas	26.8632%	🚨
openLong: min	33503 gas	1499 gas	2135.0233%	🚨
openLong: avg	167220 gas	51658 gas	223.7059%	🚨
openLong: max	252525 gas	185562 gas	36.0866%	🚨
openShort: min	33848 gas	1520 gas	2126.8421%	🚨
openShort: avg	169515 gas	51482 gas	229.2704%	🚨
openShort: max	363609 gas	181325 gas	100.5289%	🚨
redeemWithdrawalShares: min	31227 gas	1488 gas	1998.5887%	🚨
redeemWithdrawalShares: avg	63459 gas	22375 gas	183.6156%	🚨
redeemWithdrawalShares: max	161936 gas	109301 gas	48.1560%	🚨
removeLiquidity: min	31323 gas	1530 gas	1947.2549%	🚨
removeLiquidity: avg	218771 gas	151225 gas	44.6659%	🚨
removeLiquidity: max	376398 gas	325781 gas	15.5371%	🚨

This comment was automatically generated by workflow using github-action-benchmark.

[jalextowle]

LGTM once the remaining file is renamed.