Add conditional provider

[Tarmil]

Add providers for conditions on static values. They are in the String, Int and Bool subnamespace depending on the type they act on.

• IF<cond, Then = x, Else = y>.Value for if/then/else
• EQ<x, y>.Value, NE<x, y>.Value for (in)equality
• LT<x, y>.Value, LE<x, y>.Value, GT<x, y>.Value, GE<x, y>.Value for comparison (Int only)
• AND<x, y>.Value, OR<x, y>.Value, XOR<x, y>.Value, NOT<x>.Value for boolean operations (Bool only)