feat(vwc-popup): change anchorEl to anchorId (#1214)

* change anchor to id

* Update components/popup/src/vwc-popup-base.ts

Co-authored-by: yinon <yinon@hotmail.com>

* set anchorEl as getter

* remove first updated

* refactor code

* update tests

* update tests

* update ui test

* remove change event

* add anchor tests

* Update components/popup/test/popup.test.js

Co-authored-by: Yonatan Kra <yonatan.kra@vonage.com>

* Update components/popup/test/popup.test.js

Co-authored-by: Yonatan Kra <yonatan.kra@vonage.com>

* add comment to test

* update getAnchorById

* add anchorEl property

* add IntersectionObserver

* add TODO

* delete ui test

Co-authored-by: yinon <yinon@hotmail.com>
Co-authored-by: Yonatan Kra <yonatan.kra@vonage.com>