feat: Collection Icons (#1281)

* wip: Working for creation, and display

* feat: IconPicker

* fix

* feat: Invert collection icon color when dark in dark mode

* Improve readability of dropdown menus in dark mode
Suggest icon based on collection name

* Add additional icons
Tweaks and final polish

* fix: Write default icon as empty icon column

* feat: Improve icon selection logic
add more keywords
Improve icon coloring when selected and in dark mode

* lint

* lint

server/models/Collection.js

@@ -19,6 +19,7 @@ const Collection = sequelize.define(
     urlId: { type: DataTypes.STRING, unique: true },
     name: DataTypes.STRING,
     description: DataTypes.STRING,
+    icon: DataTypes.STRING,
     color: DataTypes.STRING,
     private: DataTypes.BOOLEAN,
     maintainerApprovalRequired: DataTypes.BOOLEAN,
@@ -46,6 +47,12 @@ const Collection = sequelize.define(
   }
 );
 
+Collection.addHook('beforeSave', async model => {
+  if (model.icon === 'collection') {
+    model.icon = null;
+  }
+});
+
 // Class methods
 
 Collection.associate = models => {