I've added a few more tests regarding unescaped quotes with escapes.

It is not possible to have full relaxation of unescaped quotes. This is due to it being impossible with the state machine alone to resolve the end of a value.

To give an example, let's inspect the following line. The CSV file has two columns, name,age, and the configuration would be delim = ',', quote = '"', escape = '"'.

For example:

""Oogie Boogie", "sir", 4

In one pass, it is impossible to assert whether this line has 2 or 3 columns, since we have a quote " followed by a delimiter , in different places. Even though the intention seems to be obvious.

I think this can only be supported with the auto-correction idea, where we can force the line to match our schema, but that is outside the scope of this PR.