Bug with keys with dot like "a.b"

[mixalbl4-127]

Example:

const diffs = diff({ x: "y" }, { "a.b": "c", x: "y" });
// {$set: {a.b: "c"}}
const result = apply({}, diffs);
// {a: {b: "c"}}

lib must escape dots in names because apply splices by dots :(
please help with it @mirek

------ Update ------
possible FAST problem solution: add new argument splitSymbol with default .
if sombody needs (like me) can change . to $=> for example and use it.
I think it’s almost impossible to find such a combination of characters in the key name.