[FE] when saving a Linearization there should be a visual indication that the save operation has not finished

[soimugeoWB]

As a user i want to know when the linearization specification has been successfully saved.

Need to implement some sort of loading operation over the postcoordination window until that save has completed.
Don't permit user to click on edit/save/cancel buttons until the operation has finished.

Steps to reproduce:

1. Cholera for postcoordination view.
2. hit on edit.
3. mms has severity as not allowed.
4. click on severity for mms and set it as allowed.
5. hit save
6. hit edit again
7. hit cancel

Expected outcome:
After clicking on cancel the state will reverted with mms set as allowed.

Actual outcome:
After clicking on cancel the state will reverted with mms set as not allowed.