feat: add initial Popover component implementation

[web-padawan]

Description

Part of https://github.com/vaadin/platform/issues/5271

The following logic is implemented:

• adding children
  • the logic and PopoverChildrenTest copied from Dialog
• implementing HasStyle
  • the logic and PopoverHasStyleTest copied from Dialog
• setTarget() and getTarget()
  • including a logic that checks for target detach / reattach
• setFor() and getFor()
• setPosition() and getPosition()
  • the PopoverPosition enum is a copy of TooltipPosition

Type of change

• Feature

[sonarcloud[bot]]

Quality Gate passed

Issues
26 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
3.1% Duplication on New Code

See analysis details on SonarCloud