Refactor search queries: Introduced QSSQuery

Purpose is to seperate certain logic from SQLite and generalize it more.
Even though we only have Sqlite atm, in general the database layers
must be stupid as possible, while QSSQuery should do most of the hard work.

Fixes in Tokenizer logic.
Switched to C++17.

cli/cli.pro

@@ -1,6 +1,6 @@
 QT -= gui
 QT += sql concurrent
-CONFIG += c++11 console
+CONFIG += c++17 console
 CONFIG -= app_bundle
 
 # The following define makes your compiler emit warnings if you use
@@ -32,7 +32,8 @@ SOURCES += \
     databasefactory.cpp \
     sqlitedbservice.cpp \
     logger.cpp \
-    commandsearch.cpp
+    commandsearch.cpp \
+    commandlist.cpp
 
 HEADERS += \
     encodingdetector.h \
@@ -53,7 +54,8 @@ HEADERS += \
     databasefactory.h \
     sqlitedbservice.h \
     logger.h \
-    commandsearch.h
+    commandsearch.h \
+    commandlist.h
 INCLUDEPATH += /usr/include/poppler/qt5/ /usr/include/quazip5