Feature Request: Allow mapping of data elements to the XDM object within the Action Component within Rules.

### Expected Behaviour

Within Launch, a user should be able to map a data element to an XDM node within the Rule Action Component of the XDM / AEP SDK extension. Not only will this same time, but it will make migration to alloy much easier and lead to faster adoption. This is the functionality we have now with the Adobe Analytics Extension.

A user should also be able to set global variables in the AEP web SDK extension configuration screen as well like the Analytics extension does now as well.

### Actual Behaviour

### Reproduce Scenario (including but not limited to)

#### Steps to Reproduce

#### Platform and Version

#### Sample Code that illustrates the problem

#### Logs taken while reproducing problem

Review the current AEP web SDK extension configuration screen and Rule Action Component, then compare their behavior with the existing Adobe Analytics Extension. Define how data elements should map to XDM nodes and how global variables should be configured; done means both requested capabilities are supported and their behavior is covered by appropriate tests.

Written by the indexing model from the issue text.