PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/DevelopmentWorkflow.md#running-unit-tests-application.
• Tests for the changes are included - https://github.com/NativeScript/NativeScript/blob/master/tools/notes/WritingUnitTests.md.

What is the new behavior?

This PR enhances some points around TextBase Span interaction and view disposal.
More specifically:

• Added linkTap event support for other iOS views that nest spans
• Prevent android span from setting parent background color to itself since it doesn't react to changes of that property. Unless background color is specified to the span directly, it's going to be transparent
• Added few missing nativeTextViewProtected references
• Improved view disposal for classes that inherit from TextBase as they had leftovers after android activity recreation
• Removed 2 assignments of userInteractionEnabled from TextBase as they were unneeded and had conflicts with isUserInteractionEnabled property. Core already sets that property to true for the views that need it in createNativeView call
• HTMLView will remove extra padding using the documented UIEdgeInsetsZero