Add users and connections management

[Tristan-WorkGH]

Initial version of gridadmin with users management and connections view.

[antoinebhs]

The button Add user is not shown in the interface

[flomillot]

Many commented code / TODO
Problem with routing : it's not smooth at all on tab switching, I feel like the whole page is refreshed

[flomillot]

Suggested change

	const AppWrapperWithRedux: FunctionComponent = () => (
	const AppWrapperWithRouter: FunctionComponent = () => (

Or something like that...

[flomillot]

I don't see the point will all these wrappers, they are really necessary ?

[Tristan-WorkGH]

No

That was to keep the idea of a component by provider (redex, intl, style, redux) like started gridapp-template.

[flomillot]

Suggested change

	const AppWrapper: FunctionComponent = () => (
	const AppWrapperWithRedux: FunctionComponent = () => (

[flomillot]

Why a function ?

[Tristan-WorkGH]

It's a structure config with components having dependencies in React context, so I can't per-iniitialize it in a constant outside.

[antoinebhs]

There is a glitch in the display when various users are added:

It also looks like the table can grow vertically while we would probably expect a slider inside the table with a fixed height?: