Fix indentation of the closing quotes of a multiline string literal

[paul-dingemans]

Fix indentation below:

val bar = """
    some text
         some more text
"""

to

val bar = """
    some text
         some more text
    """

However, above might be a debatable choice. Therefore I left following TODO in a test:

        // TODO: What is the proper way to place the opening and closing quotes of a multi line string value? Note that
        //  the actual content of the multi line string is never been changed as required by ktlint maintainers
        //     val foo =
        //        """
        //        line1
        //        line2
        //        """
        //  or
        //     val foo = """
        //        line1
        //        line2
        //        """
        //  or
        //     val foo = """
        //     line1
        //     line2
        //     """
        //  or
        //     val foo = """
        //        line1
        //        line2
        //     """
        // First option would be most in line with function parameter. Second option is also acceptable. Third option
        // (previous behavior) is not logical as there is no continuation kind of indent visible. Last option is not in
        // sync with function parameter.

I would like your opinion about it, so that I can finalize this PR.

This changes also includes the fix for #1127 as it has a comparable problem with the closing quotes.

[romtsn]

Hm, I'm a bit confused, the description doesn't look relevant to the PR itself, or does it? Also, what part of the diff actually fixes the closing quote? I only see changes relevant to the opening quote if it's placed on a newline so far...

[romtsn]

Why did we remove the check for trimIndent?

[paul-dingemans]

Hm, I'm a bit confused, the description doesn't look relevant to the PR itself, or does it? Also, what part of the diff actually fixes the closing quote? I only see changes relevant to the opening quote if it's placed on a newline so far...

Sorry about the confusion. I should have stated more clearly that I need input before being able to solve this entirely. I mentioned a debatable choice in the initial description. In one of the other discussion about indentation, you mentioned that you like to align the closing quotes with the opening quotes. This PR was aiming to solve that in the end. Currently the following is allowed:

val foo = """
     line 1
     line 2
     """

How should the closing quotes be aligned in this case? Aligning would mean, the following.

val foo = """
     line 1
     line 2
               """

I can not see this as an acceptable solution.

Another solution, would be to wrap the opening quotes:

val foo = 
     """
     line 1
     line 2
     """

This is my preferred solution, but it can be considered as breaking with previous ktlint version.

The removal of the trimIndent function is possible since we decided that indentation in multiline raw string literals is never changed. Therefore it is not relevant whether this literal is followed by trimIndent, trimMargin, anything else or nothing at all. It has no relation with the goal of the PR and should have been requested in a separate PR.

If you answer my previous question about the placement of the closing quotes, then I will split this PR in separate PR's with a single change in each.