As ESL consumer, I want to have a modal dialog component implemented on the ESL side.

The scope of features to support:

• ESLToggleable based implementation (to support ESLTrigger as an activator and unified interface)
• Auto move to the body to prevent overflow hidden from taking effect on esl-modal
• Support for the scroll lock strategies
• Support for the separate customizable backdrop element (attention to 'native' scroll lock strategy)
• Support for the basic focus trap
• provide the styles to support basic modal

Out of MVP scope:

• [🚀 esl-modal]: place a placeholder element in place of the esl-modal initial position #1751
• look of template using (WebComponents standard extra capabilities)
• [🚀 esl-modal]: create/rethink lifecycle events #1754
• [🚀 esl-modal]: support ootb simple appearing animations #1755
• [🚀 esl-modal]: ability to manage modal instances from JS #1756