Create experiment flow implementation

Frontend wise most of the work is done, the entry point is the topbar button as per screenshot attached.


- Implementation will be based on a cordmap stable branch to be provided (cc: @neuroBazzi )
- Each experiment will have to have at least 2 mandatory files, the key and the data files.
- The user can upload multiple pairs of these files (screenshot below)
- Each pair of files means a cordmap run, each cordmap run means 1 population generated
- The population name will be given by the the data filename
- For as many pairs of files given there should be as many populations in the experiment (in the future this will change, a data file might contain multiple populations but this is not the case in the immediate future).
- Once the button to create the experiment, the experiment tile should be created and (I guess a spinner) on that tile will be visible to indicate that the experiment is getting created (as per mockups).