Update _toolTip even if toolTipText isn't available

[dotMorten]

Fixes

Allows adding custom content to the tooltip.
The problem with replacing the tooltipText is that the tooltip completely stops working. I want the container to still work and get placed. The code was doing an unnecessary null check on an object that wasn't being used.

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

Override the style in a subclass that replaces tooltipText with something else makes tooltip stop working.

What is the new behavior?

Presence of the ToolTipText textblock is no longer required.

PR Checklist

Please check if your PR fulfills the following requirements:

• Created a feature/dev branch in your fork (vs. submitting directly from a commit on main)
• Based off latest main branch of toolkit
• Tested code with current supported SDKs
• New component
  • Documentation has been added
  • Sample in sample app has been added
  • Analyzers are passing for documentation and samples
  • Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• Tests for the changes have been added (if applicable)
• Header has been added to all new source files
• Contains NO breaking changes

Other information

[niels9001]

LGTM! Thanks @dotMorten !