Switch ~ from postfix -> prefix/binary

[d-torrance]

This has been discussed before (e.g., #3183 (comment)). The original reason for it being a postfix operator was sheafification, but that has used ^~ since #3567.

As a prefix unary operator, it makes much more sense for the remaining methods (bitwise negation of integers). We also add it as a binary operator for potential other uses such as equivalence relations (hence the choice to use the same precedence as == and friends) or building formulas in the RInterface package.

Draft for now for discussion since this is a breaking change.