Imports which are only used in code blocks which are suppressed for ktlint should not be reported as unused as removal results in compilation errors.

Refactored the code so that a rule can be marked with interface `IgnoreKtlintSuppressions` to indicate that all suppression for this rule are to be ignored.

Closes #2696

The former SuppressionLocator lambda and object SuppressionLocatorBuilder are now replaced with the class SuppressionLocator. Upon each check whether a ASTNode has to be suppressed, it is also determined whether it is needed to rebuild the suppression hints. This is only needed when the code that is represented by the AST has been changed.

The CodeFormatter no longer has to rebuild the suppression locator after autocorrect. This responsibility is now moved into the RuleExecutionContext and SuppressionLocator itself.

The former SuppressionLocator lambda and object SuppressionLocatorBuilder are now replaced with the class SuppressionLocator. Upon each check whether a ASTNode has to be suppressed, it is also determined whether it is needed to rebuild the suppression hints. This is only needed when the code that is represented by the AST has been changed.

The CodeFormatter no longer has to rebuild the suppression locator after autocorrect. This responsibility is now moved into the RuleExecutionContext and SuppressionLocator itself.

…6-no-unused-imports