Fix suppression handling when 'formatter:on' not properly specified

[paul-dingemans]

Description

Fix suppression handling when 'formatter:on' not properly specified

If the 'formatter:on' tag is not specified in the same scope as the 'formatter:off' tag, then the IndentationRule might throw an exception as the IndentationContextStack is not properly cleaned.

Also, cleaned up of CommentSuppressionHint.EOL type as it was not used since replacing the EOL suppression hints in 1.0 release.

Closes #2695

Checklist

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• Commit message are well written. In addition to a short title, the commit message also explain why a change is made.
• At least one commit message contains a reference Closes #<xxx> or Fixes #<xxx> (replace<xxx> with issue number)
• Tests are added
• KtLint format has been applied on source code itself and violations are fixed
• PR title is short and clear (it is used as description in the release changelog)
• PR description added (background information)

Documentation is updated. See difference between snapshot and release documentation

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• Release documentation in case documentation is related to a released version of ktlint and has to be published as soon as the change is merged to master