Make sub-line breakpoints work when debugging Vyper or other languages

[haltman-at]

Issue

Currently these work by AST node ID, and so only work for Solidity and Yul. These should be changed to work by source range instead, so they can work for anything. Note that this would be a breaking change to the debugger, but not one that should really affect anyone else (the Teams debugger (@kevinbluer) doesn't support sub-line breakpoints yet, although who knows if it might in the future).