Skip lines that are strictly inside of a multi-line string for indentation evaluation

[aiday-mar]

In relation to #209519

As part of the indentation improvements we want to do, we would like to skip lines that are strictly inside of a multi-line string, when evaluating indentation

[aiday-mar]

More specifically after discussing with colleagues, we want to avoid reindenting tokens inside of strings, and change the indentation when pasting into a string.