Add dedicated PartyVoteKickDurationSeconds constant for vote-kick timeout

[mfranca0009]

Summary

Currently, PartyManager.VoteKick in Maple2.Server.World/Containers/PartyManager.cs (around line 406) reuses Constants.PartyVoteReadyDurationSeconds as the timeout duration for the vote-kick Thread.Sleep call. A TODO comment in the code already acknowledges this is incorrect.

Expected Fix

1. Add a new PartyVoteKickDurationSeconds variable to Constants (Maple2.Model/Metadata/Constants.cs) as a custom constant with the correct value. There isn't a key in constants.xml for such a value.
2. Replace the use of Constants.PartyVoteReadyDurationSeconds in the Task.Factory.StartNew lambda inside VoteKick with Constants.PartyVoteKickDurationSeconds.
3. Remove the TODO comment once resolved.

Context

• Identified during review of PR #661 (Remove hardcoded server constants and use parsed constants from Server.m2d / constants.xml #661 (comment))
• Deferred from PR #661 because the correct constant value has not yet been determined.

Requested by

@mfranca0009

[mfranca0009]

The issue may have been mentioned during initial implementation of the vote kick functionality: #11.