Adding basic functionality

[tbembersimeao]

Review steps:

• [x] Make sure README provides a clear, complete and straight forward documentation
• [x] Enable the module in a project of your choice
• [x] Add a @SURVEY-PARTICIPANT-IP to a field (make sure to add it from the action tags popup in order to check if the new action tag has been properly introduced to the list of tags)
• [x] Open a public survey containing the action tagged field
• [x] Make sure the field is invisible, then save
• [x] Go back to REDCap, then open the data entry version of the submitted survey
• [x] Make sure you see a read-only field containing a valid public IP address

[marlycormar]

@tbembersimeao I tested the module with table-based authentication and shibboleth; it works on both. Please feel free to merge, as I lack the permissions to do so.

Minor points:

• The json file is missing the min required RC version.
• The License can be made shorter (see the License in linear_data_entry_workflow).