Show testing warning in software center

[DavidePrincipi]

If any Testing switch under Settings > Software Repositories is turned on, the Software Center must display a "⚠ warning inline notification":

 Testing repositories enabled

 Some software repositories include non-stable versions of applications 

 [Go to Software repositories]

[ns8 crash course]

[andre8244]

Test case

core 2.5.3-dev.4

• Go to Settings / Software repositories
• Edit a repository
• Enable Testing toggle and save
• Go to Software center
• Ensure that a warning notification is shown at the top of the page

[nrauso]

Test case: VERIFIED

Now a notification banner appears on top of Software Center if a testing repo is enabled:

[DavidePrincipi]

Released in

• https://github.com/NethServer/ns8-core/releases/tag/2.5.3