Initial commit for Postgres Operator UI (#613)

* Initial commit for our basic Postgres Operator UI:
 * Create and modify Postgres manifests
 * Watch Operator Logs in the UI
 * Observe cluster creation progress
 * S3 Backup browser for clone and restore

Many thanks to Manuel Gomez and Jan Mussler for the initial UI work a long time ago!

ui/app/.eslintrc.yml

@@ -0,0 +1,27 @@
+parserOptions:
+  sourceType: module
+env:
+  browser: true
+  node: true
+  es6: true
+extends: 'eslint:recommended'
+rules:
+  indent:
+    - error
+    - 4
+  linebreak-style:
+    - error
+    - unix
+  quotes:
+    - error
+    - single
+  prefer-const:
+    - error
+  no-redeclare:
+    - error
+  no-unused-vars:
+    - warn
+    - argsIgnorePattern: "^_"
+  semi:
+    - error
+    - never