feat: Add new "Change Editor" option to note context menu (#823)

* feat: add editor icon

* refactor: remove 'any' type and format

* refactor: move NotesOptions and add ChangeEditorOption

* refactor: fix type for using regular RefObject<T>

* feat: add hide-if-last-child util class

* feat: add Change Editor option

* feat: make radio btn gray if not checked

* fix: accordion menu header and item sizing/spacing

* feat: add Escape key to KeyboardKey enum

* refactor: Remove Editor Menu

* feat: add editor select functionality

* refactor: move plain editor name to constant

* feat: add premium editors with modal if no subscription

refactor: simplify menu group creation

* feat: show alert when switching to non-interchangeable editor

* fix: change editor menu going out of bounds

* feat: increase group header & editor item size

* fix: change editor menu close on blur

* refactor: Use KeyboardKey enum & remove else statement

* feat: add keyboard navigation to change editor menu

* fix: editor menu separators

* feat: improve change editor menu sizing & spacing

* feat: show alert only if editor is not interchangeable

* feat: don't show alert when switching to/from plain editor

* chore: bump snjs version

* feat: temporarily remove change editor alert

* feat: dynamically get footer height

* refactor: move magic number to const

* refactor: move constants to constants file

* feat: use const instead of magic number

app/assets/templates/directives/editor-menu.pug

@@ -1,30 +0,0 @@
-.sn-component
-  .sk-menu-panel.dropdown-menu
-    .sk-menu-panel-section
-      .sk-menu-panel-header
-        .sk-menu-panel-header-title Note Editor
-      menu-row(
-        action='self.selectComponent(null)',
-        circle="!self.selectedEditorUuid && 'success'",
-        label="'Plain Editor'"
-        )
-      menu-row(
-        ng-repeat='editor in self.state.editors track by editor.uuid'
-        action='self.selectComponent(editor)',
-        circle="self.isEditorSelected(editor) && 'success'",
-        label='editor.name',
-        subtitle="self.isEditorSelected(editor) && 'Version ' + editor.package_info.version",
-        )
-        .sk-menu-panel-column(
-          ng-if='editor.conflictOf'
-          )
-          .info(
-            ng-if='editor.conflictOf'
-            ) Conflicted copy
-      a.no-decoration(
-        href='https://standardnotes.com/plans',
-        ng-if='self.state.editors.length == 0',
-        rel='noopener',
-        target='blank'
-        )
-        menu-row(label="'Download More Editors'")