Enhancement
                         
                    
                    The tooltips of UI elements should be rendered via HTML templates, which were introduced in ticket #27321.
Implementation
The tooltips are rendered with the help of HTML templates:
- com.top_logic.layout.tooltip.Icons.TOOLTIP_WITH_CAPTION: Tooltip with caption.
 - com.top_logic.layout.tooltip.Icons.TOOLTIP_WITHOUT_CAPTION: Tooltip without heading.
 
The content of the tooltip is, for example, the translation of the I18N key for theme variables, which results from its fully qualified name.
Code migration
A tl:DisplayContext has been added to the signature of the following methods:
- AbstractControlBase.writeControlAttributes
 - OverlibTooltipFragmentGenerator.writeTooltipAttributesPlain
 - OverlibTooltipFragmentGenerator.writeTooltipAttributes
 - AbstractTreeContentRenderer.writeTextLinkStart
 - HTMLUtil.writeImageTooltip
 - HTMLUtil.writeImageTooltipHtml
 - TableRenderer.writeGroupRows
 - TableRenderer.writeGroupColumnContent
 - LegacyTreeContentRenderer.writeTextLinkStart
 
Test
- Refactoring, no test.
 
- Start the demo application and navigate to the theme editor. For example, select the theme dezentModern and then filter the theme variable TOOLTIP_WITH_CAPTION. If you hover over the theme variable, you will get a tooltip with caption.