Avoid naming GNOME core apps by their common noun name

Originally created by @sajolida on #15669 (Redmine)

During the user testing of the VeraCrypt beta, participants had a hard time understanding what Files and Disks refer to.

As we were also dealing with encrypted file containers and disk partitions and I used very short section titles (“Using Files” and “Using Disks”), the confusion was maximum. But I think understood that these naming are not clear enough when using in the context of documentation and would highly gain from being clarified.

I think that using a longer and more descriptive name would help, for example:

• the Files browser
• the Disks utility

I’ll also consider adding the logo of the application as it appears in the activities overview.

We should also add this to our documentation style guide.

Feature Branch: befcec1e48

Parent Task: #14480 (closed)