Add option to select patient or user from a list

[faizalMo]

Add user switching and patient switching capability in the UI.

Load the list of available patients for selection in the ‘Change Patient’ settings menu options. Also, added a new option ‘Change User’ under settings menu which lists available Practitioners to select.

[kolkheang]

Thanks @faizalMo for contributing to this project! I like the idea of having some defaults.

I have not looked at the code yet but I was able to pull in your PR into the branch and built it locally to check it out. I have a few comments regarding what I'm seeing in the UI.

1. The drop downs for both the users and the patients default list are limited. Further more, this drop down does not allow for a text entry. So, the users are stuck with this limited option. I'm proposing that the drop down should also be able to type in, similar to html5 <datalist> so that it serves both purposes.

2. The FHIR server can be changed. It's useful when we want to test against various implementations of FHIR servers. What you have is only the defaults for https://api.hspconsortium.org/cdshooksdstu2/open. We could implement such a way that, if there are defaults, use the defaults. Otherwise, don't use any defaults but still allow users to input values manually.

3. The current behavior doesn't work after changing the FHIR server. The dialog to change the users and patients don't display anymore.

[kpshek]

Thanks @faizalMo for this PR -- we really appreciate the contribution! I think @kolkheang's comments are spot on and it is important for us to consider the switching FHIR server behavior with any changes we make to the Sandbox as this is a heavily used feature of the Sandbox.

Let us know if you have any questions.

[faizalMo]

Thanks for the feedback. Considering not all FHIR servers would have implemented features like pagination or respect the _count query param, it will be really hard to come up with a general solution for this. I have also noticed that 1 of the opensource fhir server didnt even have "id" for the Patient resourcetype in the search result, which will break the current implementation in this PR.

This PR was a result of changes that made my life easier trying to switch between patient and users in the sandbox. Considering the changes are not very robust in its current form and would break existing features, I will close this PR for now.