Add "loading" animation or text to all sponsors

[chrismaree]

All sponsors tab takes a bit longer to load than the rest of the app. The user should be told that it's currently loading while the data is retrieved.

[Tumbiola]

Needs loading animation when finalizing mint to alert sponsor the selection received input and is loading.
Avoids pressing button numerous times and multiple unnecessary transactions due to no reaction when pressed,
sits idle.
Added note: after selecting, all user added numerical input should be reverted back to zero. That would solve the transaction issue.
Also : Dead link: - Read more about the GCR here.

This :

Create 0 YD-ETH-MAR21 with 0 WETH