Remove the component selectors for subcomponent styles

Instead, use :host in conjunction with ::deep

docs/release-notes-editor.txt

 Editor
 ======
+1.26.1
+- Fix styling issues with some elements in version 1.26.0
+
 1.26.0
 - Set the default language of the editor to German
 - Add handling of empty and invalid unit definitions

docs/release-notes-player.txt

 Player
 ======
+1.20.1
+- Fix styling issues with some elements in version 1.20.0
+
 1.20.0
 - Implement readonly for text fields of cloze elements
 - Set the default language of the player to German