Add auction start functionality to vault

[cmontecoding]

No description provided.

[Flocqst]

Nice work, starting logic is good but it is still missing small adjustment for starting the auction automatically on vault operations.

Tests will have to be adapted slightly once new logic is in.

[Flocqst]

This should be performed on vault operations (deposit/redeem) when possible so that no one has to call the auction manually.

What you should be doing instead is having a modifier, something like that for instance :

modifier checkAuction() {
    if (isAuctionReady()) {
        createAuction();
    }
    _;
}

and add it to the deposit/redeem functions.

[Flocqst]

_startingBid logic should be handled directly in the auction factory, KSX vault should only have "vault logic" and the logic to start auction. (same as bidBuffer).

[Flocqst]

You can remove this and make function internal as the check will be performed in the modifier.