Re: [pgAdmin][RM6130] React based framework for properties dialog and port Server Group, Server and Database dialogs

Hi Hackers,

Attached patch marks the beginning of migrating properties dialog/tab to React based code, which is easy to maintain, performant and testable using automation.

Patch includes:

- Framework for creating React based dynamic form view out of a pre-defined UI schema. Previously, it was based on Backform/Backbone.

- The new framework and components will use MaterialUI as base. Previously, Bootstrap/Backform/jQuery components were used.

- The new code uses JSS instead of CSS since material ui and most modern React libraries also use JSS. In future, this will allow us to change the theme in real-time without refresh.

- 90% code covered by 80-85 new jasmine test cases.

- Server group node UI Schema migration to new, with schema test cases.

- Server node UI Schema migration to new, with schema test cases.

- Database node UI Schema migration to new, with schema test cases.

- Few other UI changes.

PS: Until all the nodes are migrated, this will not go in the main branch.