Fix missing localization

This addresses some of what's reported in ticket #14637.

* Keymap preferences: Localize key labels. Translators have
to be careful not too use too long words here...

* Media preferences: Fix typo "SoundFonts" -> "SoundFont"
The two popup menus, Video input/output, both use "<none>",
which when the catkeys are collected is reduced to one item.
Apparently, Italian likes to have different tranlsations for
them. I hope to fix that by using B_TRANSLATE_COMMENT with
differing comments. Not sure if that'll work...

* Network preferences: Localize "on/off" and "Enable/Disable"
in the Services.

* Repositories preferences:
Add RepoRow.cpp to DoCatalogs.

* Shortcuts preferences: Localize "Left/Right/Both/Either/None"

* Bluetooth replicant: Localize menu items and alerts.

* DeskCalc: Localize button names.

* HaikuDepot:
- Use BStringFormat and variables to replace for the WorkStatusView.
- Put package name in single quotes; nicer if you have package names
with spaces.
- Avoid leading and trailing spaces in translatable strings. Those
can be overlooked b the translator.
- Use B_UTF8_ELLIPSIS instead of "...".

Change-Id: Ia32908f9faad5188aa87c918c31229277decbda9
Reviewed-on: https://review.haiku-os.org/631
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

Fix crash with missing midi_settings

fActiveSoundFont wasn't initialized when there's no midi_settings file.
Don't allocate it on the heap, the object get implicitely initialized to
an emtpy string.
Tiny style fix.
Thanks to AnEvilYak for his consultation.

Fixes #13402.

Media prefs: fix crash in empty MIDI soundfont list

Check if soundfont list is empty or we crash when double-clicking
into the list.

Fixes #13091.

Improved MIDI section of Media preferences

* Get rid of the "Actve Sound Font:" BStringView below the BListView.
Now the selected SoundFont is the active SF.
* If there's only one SF available, select it automatically.
* Added a BStringView below the list and only give feedback when needed:
- if no SF is installed
- if the user has to select a SF
* Double-clicking an entry opens its location in Tracker.
* Added node-monitoring to live-update the list of available SFs.
Note: Un/installing a package doesn't trigger a notification (related
to #9970 ?).

MediaSettings: Don't change the active soundfont
if the user clicked on empty space

MediaPreferences: midi: added a BStringView with the currently active soundfont

Midi: Remove some duplicated code
Introduced new private read/write_midi_settings() and used them
in MidiSettingsView and SoftSynth.

MidiSettingsView: renamed box label
Renamed box label from "SoundFont" to "Available SoundFonts", hopefully
improves the user experience by making it clearer that this is a list
of the available soundfonts.

Improved comment. Added TODO

CID 1249930: Don't scanf uninitialized buffer

Would happen in case of a missing config file, for instance.

Midi preflet: remove check for big_synth.sy, since we don't create it
anymore.
Fixed comment.

Media Preflet: Use BPathFinder::FindPaths() instead of the C method.
This way we can use BStringList and get rid of the manual deallocation.

Media Preflet: Don't leak paths.

Integrate MIDI settings with the Media preflet.
More or less working.

Midi: Remove some duplicated code
Introduced new private read/write_midi_settings() and used them
in MidiSettingsView and SoftSynth.

MidiSettingsView: renamed box label
Renamed box label from "SoundFont" to "Available SoundFonts", hopefully
improves the user experience by making it clearer that this is a list
of the available soundfonts.

Improved comment. Added TODO

CID 1249930: Don't scanf uninitialized buffer

Would happen in case of a missing config file, for instance.

Midi preflet: remove check for big_synth.sy, since we don't create it
anymore.
Fixed comment.

Media Preflet: Use BPathFinder::FindPaths() instead of the C method.
This way we can use BStringList and get rid of the manual deallocation.

Media Preflet: Don't leak paths.

Integrate MIDI settings with the Media preflet.
More or less working.