change whitespace from normal to pre-line

[christopherpickering]

For multiline tooltips it would be nice to accept a multi line input and preserve line breaks.
pre-line will keep the source line breaks.

[christopherpickering]

@wikiki any change on merging?

[suterma]

While this works well as intended, I would not personally like this to be the default. In my Vue app, the linter might choose to break text lines (or I do for readability) and I am happy to have the default as is.

That said, I would suggest to make this either optional with a class like 'has-tooltip-multiline-pre-line' or better yet, with a new scss variable like $tooltip-whitespace