config URL param for threshold

[jchris]

this should look like the fragmentation config

[jchris]

#185

[valorant-dhruv]

Here's what I am thinking. Because the threshold is either what end user passes ( who isn't aware of limitations of some connectors) or a hardcoded value, it's better to add a connector parameter inside the super this class and create a new threshold function which either returns a default value or threshold value specific to the connnector. We will keep updating this parameter for a particular database depending on which remote is being used.

[valorant-dhruv]

Because this is inside core fireproof, I am not using gateway functions and URLs here.