Finalise the parameters in parachainStaking #921
Description
Especially the following parameters, are they still up-to-date?
pub const MinCollatorStk: Balance = 50 * DOLLARS;
pub const MinCandidateStk: Balance = 50 * DOLLARS;
pub const MinDelegation: Balance = 50 * DOLLARS;
pub const MinDelegatorStk: Balance = 50 * DOLLARS;