Disable submit/save buttons in the GCI after a single click

[h-tong]

Some duplications of data in the GCI seem to have been caused by a repeated click on the submit or save button when the interface is seemingly unresponsive, but it was possibly just slow.

1. Add a disable/busy icon to the "Submit" button when creating a new gene-disease record
2. Add a disable/busy icon to the individual, experimental, case-control "Save" buttons when the user tries to add/edit the evidence score via the "View/Score" link.

Resolves possible causes of #2054, #2058

[cgpreston]

@h-tong , can we close this with the rearchitecture?

[h-tong]

@cgpreston Yes, we can close this.

[cgpreston]

Thanks @h-tong