Fix Clock. Tooltip calendar text overflows(#2240)

[LukashonakV]

Hi @Alexays, @FilippoBonazziSUSE this MR solves #2240
Actually here it's GtkLabel wrong behavior with tooltips. Even @BrianCArnold has found workaround it's better to have code fixed.
Temporary for now I replaced clock label with Gtk::TextView. In order to have the same styling as it was for tooltips in the system, users should use next css styling

textview#clock.tooltip, textview#clock.tooltip text {
   background-color: inherit;
   padding: inherit;
}

For now I'm trying to write test case in pure C in order to provide it gtk maintainers to fix gtk

So fixed variant looks good

[LukashonakV]

Hi @Alexays , ping )

[LukashonakV]

Hi @Alexays , finally this MR is ready to merge. According discussion here Label set_markup tooltips width for the Widget class is limited.
So for now I found the better solution using one more Gtk::Label as a tooltip for the base Clock label. And then to set_markup for this tooltip label. Such approach allows solve #2240 without any additional CSS style customization from the user

[LukashonakV]

Hi @Alexays , ping

[LukashonakV]

Hi @Alexays , ping once again )

[LukashonakV]

Hi @Alexays , any feedback ?

[LukashonakV]

Hi @Alexays , ping again

[alkar]

Amazing, thanks for this PR!

[LukashonakV]

@Alexays any feedback?

[LukashonakV]

@Alexays ?

[FilippoBonazziSUSE]

It looks like Alexays is unavailable right now (travelling, on vacation, ...). I'm sure he will see your pings once he is available again. I don't think pinging him every few hours helps.

[Alexays]

LGTM, and yes i was on vacation :)

[FilippoBonazziSUSE]

Thanks @LukashonakV for providing the fix, can't wait to try it out.