Strings Ending in Escaped Backslash are Inproperly Lexed

It was found that the lexer does not properly handle strings ending in an escaped backslash. For example:

description "some description that ends in a backslash \\"

The lexer will not terminate the string at the last double quote. Instead it will interpret it as part of the string and continue lexing the next lines as though it belongs to the string.

I have a commit which fixes this issue & tests it. I'll link it to this bug. I don't know how to organize the unit tests I've included so please let me know which packages it belongs to.