Redevelop the Inspector widget

[bennothommo]

Please see #498 for more information on this PR, and keep this thread only for discussing the technical implementation.

[what-the-diff[bot]]

• Removed .eslintignore file
• Updated the eslintrc.json to include new files and folders in assets/ui folder
• Changed manifest from !function(){"use strict";var r,n={},e={};function t(r){var o=e[r];if(void 0!==o)return o.exports;var i=e[r]={exports:{}};return nr,i.exports}t... TO ...!function(){"use strict";var n,e={},r={};function t(n){var o=r[n];if(void 0!==o)return o.... (removed var r = self...)
• Added a few translations for German language pack - "widget_remove_confirm":"Dieses Widget entfernen?","invalid_image_empty_insert":"Bitte ein Bilddatei ausw\u00e4hlen." etc..
• The data-attr.js file was changed to use the new version of Snowboard
• AssetLoader and Url were updated for compatibility with newer versions of jQuery
• storm.js is now using a different syntax, so it needs to be regenerated from scratch (see below)
• base/base has been added as an entry point for all widgets in this directory tree; see https://github.com/octobercms/library#widgets-and-plugins
• Added Overlay element
• Added Tooltip element
• Updated inspector fields to use new elements and components where appropriate (CheckboxListField, DropdownField)
• Added a new TextField component
• Created the inspector plugin and added it to Snowboard's plugins list
• Created Popover layout for Inspector widget, which is used by default in this version of the widget (other layouts will be created later)
• Added a new file Inspector.vue
• Changed the template to use PopoverLayout component and added title, description and fields slots
• Imported Field component from ../fields/Fields.vue
• Defined props for snowboard, inspectedElement etc.. in data() function of script tag
• Computed inspectorTitle(), inspectorDescription() & layoutComponent(). Also defined layoutProps object with properties shown: this showInspector (which is false by default), placement: 'auto', fallbackPlacement:'bottom' , offsetX : 0 & offsetY :0 . This will be used as prop values when rendering element inside template section using v-bind directive
• Added a new file: modules/system/assets/ui/widgets/inspector
• Updated the package.json to include vue and less-loader as dependencies, updated devDependencies with eslint and vue-loader
• Updated winter mix js to add support for VUE 3 (vue({ version: 3 }))
• Update Request test case in tests folder so that it includes vendor files when running jest tests

[jaxwilko]

@what-the-diff 🤔