use same XYK liquidity mining pallet as hydradx

the xyk lm pallet was already there, it wasnt in the workspace.

not sure about the reuse of hydra pallet. let's ask @martinfridrich

but personally, i would leave it as is, to minimize upgrade changes. and rather create PR to change the pallet from hydra, if possible

_Originally posted by @enthusiastmartin in https://github.com/galacticcouncil/Basilisk-node/pull/659#discussion_r1592440818_