The tsm-client needs a tsm-server to do anything useful.
Without a server, automated tests can just
check diagnostic outputs for plausibility.
The commit at hand adds two tests:
1.
The command line interface `dsmc` is called,
then it is verified that the program does
* report the correct client version,
* find its configuration file,
* report a connection error.
2.
To check the GUI (and the tsm-client nixos module), we add a
vm test which uses the module to install `tsm-client-withGui`.
To verify that the GUI's basic functionality is present,
we skip over all connection failure related error
messages and open the "Connection Information"
dialog from the main application window.
This dialog presents the node name and the client version;
both are verified by the test.
Note: Our `tsm-client` build recipe consists of two packages:
The "unwrapped" package and the final package.
This commit puts the unwrapped one into the final
package's `passthru` so that tests can access
the original version string that is needed to check
the client version reported by the application.
