Kraft should bring its own Icons

There are situations where the application can not rely on an icon theme having all the required icons, as mentioned in #11 and #149:

running on a random file manager that does not have a rich theme installed
running on platforms that does not support packages "the linux way"
running from AppImage.

The solution is: Kraft is brings as much icons as possible (all?) with the bundled Qt resources mechanism (compiled in).

Questions:

Where to pick the icons from? Best bet so far: https://github.com/tabler/tabler-icons (big set, MIT License)
Pick from installed theme first and fall back on the own Kraft theme or vice versa, or go with the Kraft-Theme only?

All icons we use should be available in SVG format and under a free license that is compatible with GPL.

@Moini do you want to help?

List of Kraft Icons

First column: The name of the SVG to use - feel free to add ;-) Second column: The name of the icon in the current source Third column: The source files that mention the icon

All icons picked from https://tabler-icons.io/

new Icon Name	Icon Name in Kraft source	in files used
plus	Add	prefsdialog.cpp, prefsunits.cpp, prefswages.cpp
arrow-down	Down	prefswages.cpp
pencil	Edit	prefsunits.cpp, prefswages.cpp
X	Remove	prefsdialog.cpp, prefsunits.cpp, prefswages.cpp
receipt-tax	Taxes	prefsdialog.cpp
atom	Units	prefsdialog.cpp
arrow-up	Up	prefswages.cpp
cash-banknote	Wages	prefsdialog.cpp
calculator	accessories-calculator	templkataloglistview.cpp
logout	application-exit	portal.cpp
arrow-down	arrow-down	positionviewwidget.cpp
arrow-up	arrow-up	positionviewwidget.cpp
check	checkmark	prefsdialog.cpp
arrows-up-down	configure	positionviewwidget.cpp
file-x	document-delete	katalogview.cpp
edit	document-edit	doctypeedit.cpp, flostempldialog.cpp, katalogview.cpp, portal.cpp
file-export	document-export	portal.cpp
file-plus	document-new	docassistant.cpp, katalogview.cpp, portal.cpp
template	document-new-from-template	portal.cpp
eye	document-preview	portal.cpp
printer	document-print	portal.cpp
edit	document-properties	docassistant.cpp
copy	edit-copy	portal.cpp, prefsdialog.cpp
cut	edit-cut	portal.cpp
	edit-delete	docassistant.cpp, positionviewwidget.cpp
transfer-in	edit-paste	portal.cpp
use lock	encrypted	positionviewwidget.cpp
archive	file-library-symbolic	portal.cpp
file-plus	filenew	positionviewwidget.cpp
flag	flag	positionviewwidget.cpp
edit	folder-documents	katalogview.cpp, prefsdialog.cpp
arrow-narrow-left	go-previous	docassistant.cpp, textselection.cpp
help	help-about	portal.cpp
arrow-ramp-right	kraft_alternative	positionviewwidget.cpp
arrow-move-right	kraft_demand	positionviewwidget.cpp
coin	kraft_fulltax	kraftview.cpp, positionviewwidget.cpp
circle-0	kraft_notax	kraftview.cpp, positionviewwidget.cpp
circle-half-2	kraft_redtax	kraftview.cpp, positionviewwidget.cpp
dice	kraftdice	templkataloglistview.cpp
plus (see add)	list-add	doctypeedit.cpp, flostempldialog.cpp, numbercycledialog.cpp
minus (see remove)	list-remove	doctypeedit.cpp, flostempldialog.cpp, numbercycledialog.cpp
mail-forward	mail-forward	portal.cpp
locked	object-locked	positionviewwidget.cpp
lock-open	object-unlocked	positionviewwidget.cpp
language	preferences-desktop-locale	kraftdocheaderedit.cpp
device-floppy	quickopen-file	doctypeedit.cpp, prefsdialog.cpp
minus	remove	positionviewwidget.cpp
settings	settings-configure	portal.cpp
id-badge-2	user-identity	prefsdialog.cpp


Mail Forward		https://tabler-icons.io/i/mail-forward
User-Identity		https://tabler-icons.io/i/id-badge-2
Settings		https://tabler-icons.io/i/settings https://tabler-icons.io/i/tool
Locked/Unlocked		https://tabler-icons.io/i/lock-open https://tabler-icons.io/i/lock
Help		https://tabler-icons.io/i/help
Add/Remove		https://tabler-icons.io/i/plus https://tabler-icons.io/i/minus
Export/Backup Database		https://tabler-icons.io/i/database-export

dragotin / kraft

Kraft should bring its own Icons #175

List of Kraft Icons

All icons picked from https://tabler-icons.io/