feat!: Refactor <Area> and <ContentArea> components

[baptistegrimaud]

Description

Addresses #179.
Refactor and simplify <Area> and <AbsoluteArea> components (with breaking changes!).

Usages

To use a fixed JCR node content of a given page:

<AbsoluteArea name="yourContentNode" parent={yourPageNode}>

This would store (and create if it does not exist) the content node yourContentNode (of type "jnt:contentList") as a child node of yourPageNode (a JCRNodeWrapper).
For instance, to use the main node of the home page:

<AbsoluteArea name="main" parent={renderContext.getSite().getHome()} />

Or to use a different page (at a custom hierarchy):

<AbsoluteArea name="main" parent={renderContext.getSite().getNode("your-page/your-sub-page")} />

A content node relative to the current page can also be used:

<AbsoluteArea name="main" parent={currentNode} />

Which is equivalent to use a classic <Area>:

<Area name="main" />

[baptistegrimaud]

NB: the tests seem to fail because of Jahia/jcontent#1681

[dgriffon]

I would suggest to rename the components to avoid the confusion with Area and AbsoluteArea that are not working the same way.

[baptistegrimaud]

I would suggest to rename the components to avoid the confusion with AreaTag and AbsoluteAreaTag that are not working the same way.

It was actually decided to keep the existing Area and AbsoluteArea components names to avoid creating a third one...
But I agree that could lead to confusion to developers/integrators.

[GauBen]

I pushed an update to the library readme, tell me if it's accurate