new criterion proposal: Graphical package managers

[Kamil Paral]

During the F35 release cycle, there was a dissatisfaction that we use the
"basic functionality" criterion [1] too broadly when discussing package
manager issues (like multiple issues in plasma-discover). I was asked in
the latest QA meeting to propose a specific criterion to cover package
managers in detail. Here it is.

Please note that we already have package management partly covered in the
Basic criteria [2] and Beta criteria [3]. Please read those first,
including footnotes. The following new criterion is proposed against the
Final milestone:

~~~~~~~~~~
The default graphical package manager for a given software type must
appropriately:
* install, remove and update software, even if multiple operations are
scheduled sequentially or concurrently
* list software installed on the system
* list available software (possibly in categories, a curated list, etc)
* display metadata relevant to the selected software (e.g. the description,
screenshots, the size)
* start the selected installed software
* configure software sources (enable/disable/add/remove repositories, set
default sources) and then adjust the available software pool accordingly
* notify the user when system updates are available (taking into account
the intended frequency of such notifications)

Note: Supported functionality and design decisions
All requirements apply only if such a functionality is supported by the
package manager; it does not imply that the package manager must support
all this functionality. The requirements don't apply if some functionality
is intentionally modified as a design decision (e.g. if some software
sources can't be disabled as an intentional precaution to users breaking
their system). If there is a bug violating the design decisions in one of
the covered areas (e.g. a software source which is supposed to be always
enabled can be disabled), it's up to the blocker review team to consider
whether this bug makes the user experience or system safety considerably
worse.

Note: Refer to Basic footnotes
The footnotes for the [similar Basic criterion covering console tools][2]
regarding software types, 'appropriate' behavior, scope and so on are all
generally applicable to this criterion also.
~~~~~~~~~~

The criterion covers a lot of functionality. I'm coming from the notion
that the package manager (together with the web browser) is the most
important app on desktops, issues in it are very hard to work around for
users and provides core system functionality. That's why I think we should
have high standards for it.

Please let me hear your thoughts. Thanks.

[1]
https://fedoraproject.org/wiki/Fedora_35_Final_Release_Criteria#Default_a...
[2]
https://fedoraproject.org/wiki/Basic_Release_Criteria#software-install-re...
[3]
https://fedoraproject.org/wiki/Fedora_35_Beta_Release_Criteria#Installing...