2092 - Fix IdsMasthead layout and responsive behavior

[jmacaluso711]

Explain the details for making this change. What existing problem does the pull request solve?

This PR simplifies the structure of the ids-masthead by reducing the number of slots to a single slot. This allows for the addition of an ids-toolbar to manage button placement and toolbar functionality within the masthead.

• Refactored Layout: Updated the layout to support a more flexible and customizable toolbar integration within the masthead using the ids-toolbar component.
• Enhanced Customization: The new structure enables users to customize the toolbar's content and organization within the masthead without predefined slot constraints.
• Backward Compatibility: Ensured backward compatibility by maintaining existing methods and properties, while streamlining the usage of the masthead component.

Related github/jira issue (required):

closes #2092

Steps necessary to review your pull request (required):

• pull and run branch
• go to http://localhost:4300/ids-masthead/example.html
• Resize browser
• Buttons should overflow into the "More" button when on smaller screens

Included in this Pull Request:

• [x] Some documentation for the feature.
• [x] A test for the bug or feature.
• [x] A note to the change log.