remove excessive characters in sample xml files

VectoCore/VectoCoreTest/TestData/XML/XMLReaderDeclaration/SchemaVersion2.10/vecto_vehicle-stage_input_only_certain_entries01-sample.xml

-<?xml version="1.0" encoding="UTF-8"?>AirdragModifiedMultistepAirdragModifiedMultistep
+<?xml version="1.0" encoding="UTF-8"?>
 <tns:VectoInputDeclaration schemaVersion="2.0" xmlns="urn:tugraz:ivt:VectoAPI:DeclarationDefinitions:DEV:v2.10.2"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:tns="urn:tugraz:ivt:VectoAPI:DeclarationInput:v2.0" 

VectoCore/VectoCoreTest/TestData/XML/XMLReaderDeclaration/vecto_vehicle-stage_input_full-sample.xml

-<?xml version="1.0" encoding="UTF-8"?>AirdragModifiedMultistepAirdragModifiedMultistep
+<?xml version="1.0" encoding="UTF-8"?>
 <tns:VectoInputDeclaration schemaVersion="2.8" xmlns="urn:tugraz:ivt:VectoAPI:DeclarationDefinitions:DEV:v2.10.2"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xmlns:tns="urn:tugraz:ivt:VectoAPI:DeclarationInput:v2.0" 

VectoCore/VectoCoreTest/TestData/XML/XMLReaderDeclaration/vecto_vehicle-stage_input_only_certain_entries01-sample.xml

-<?xml version="1.0" encoding="UTF-8"?>AirdragModifiedMultistepAirdragModifiedMultistep
+<?xml version="1.0" encoding="UTF-8"?>
 <tns:VectoInputDeclaration schemaVersion="2.8" xmlns="urn:tugraz:ivt:VectoAPI:DeclarationDefinitions:DEV:v2.10.2"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:tns="urn:tugraz:ivt:VectoAPI:DeclarationInput:v2.0"