fix(ui5-button): adjust tooltips display

[unazko]

Issue:

• The default icon tooltip is displayed over the ui5-button even though there is a text
  in the ui5-button's slot.

Solution:

• The default icon tooltip should only be shown when the ui5-button is in icon-only mode
  according to the UX guidelines.

Fixes: #10824

[ui5-webcomponents-bot]

🎉 This PR is included in version v2.10.0-rc.2 🎉

The release is available on v2.10.0-rc.2

Your semantic-release bot 📦🚀

[Copilot]

Pull Request Overview

This PR adjusts the tooltip display behavior on ui5-button so that the default icon tooltip is only applied when the button is icon-only, addressing the UX issue described in #10824.

• Removed the showTooltip property from the ButtonTemplate to simplify tooltip handling.
• Updated Button.ts to only assign a default tooltip if the button is icon-only.
• Extended tests in Button.html and Cypress specs to validate the new tooltip behavior.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
packages/main/test/pages/Button.html	Added buttons with varied configurations to test tooltip behavior.
packages/main/src/ButtonTemplate.tsx	Removed the unused showTooltip prop in the icon rendering.
packages/main/src/Button.ts	Updated tooltip assignment logic to honor icon-only mode when applying the default tooltip.
packages/main/cypress/specs/Button.cy.tsx	Added a test to ensure that a tooltip is not rendered when text is present.

Comments suppressed due to low confidence (3)

packages/main/src/ButtonTemplate.tsx:50

• The removal of the showTooltip prop simplifies the template and aligns with the updated tooltip logic. Consider verifying that any related unused properties or code paths are also cleaned up to improve maintainability.

showTooltip={this.showIconTooltip}

packages/main/cypress/specs/Button.cy.tsx:242

• [nitpick] The test for ensuring no tooltip is displayed when text is present is good; however, consider using a more specific selector to target the intended button instance in case multiple buttons exist in the DOM.

cy.mount(<Button icon="home">Action</Button>);

packages/main/src/Button.ts:370

• The updated conditional assignment of 'buttonTitle' ensures that the default tooltip is only applied when the button is in icon-only mode. Please verify that cases where no tooltip is provided (and the button is not icon-only) correctly result in 'buttonTitle' remaining undefined.

const defaultTooltip = await this.getDefaultTooltip();