XWIKI-20938: Add ability to insert an image using the keyboard

...ources/Attachment/Picker/Code/AttachmentGalleryPicker.xml

...-picker-webjar/src/main/webjar/attachmentGalleryPicker.js

...rm-attachment-picker-webjar/src/main/webjar/solrSearch.js

...-plugins/src/main/webjar/xwiki-image/attachmentService.js

...editor-plugins/src/main/webjar/xwiki-image/imageWizard.js

...rm-ckeditor-plugins/src/main/webjar/xwiki-image/plugin.js

...rm-ckeditor-plugins/src/main/webjar/xwiki-slash/plugin.js

...rc/test/it/org/xwiki/ckeditor/test/ui/QuickActionsIT.java

...orm-ckeditor-ui/src/main/resources/CKEditor/EditSheet.xml

...-ckeditor-ui/src/main/resources/CKEditor/Translations.xml

...ch-solr-ui/src/main/resources/XWiki/SuggestSolrMacros.xml