[EDELIVERY-12617] add licnese headers to source files

license/eupl-1.2/header.txt

license/eupl-1.2/license.txt

license/licenses.properties

pom.xml

smp-angular/src/main/resources/META-INF/web-fragment.xml

.../ec/smp/spi/examples/DomiSMPResourceExampleExtension.java

...a/ec/smp/spi/examples/def/DomiSMPJsonResourceExample.java

.../smp/spi/examples/def/DomiSMPPropertyResourceExample.java

...u/europa/ec/smp/spi/examples/handler/AbstractHandler.java

...c/smp/spi/examples/handler/DomiSMPJSONHandlerExample.java

...p/spi/examples/handler/DomiSMPPropertyHandlerExample.java

...u/europa/ec/smp/spi/examples/handler/ExampleEntityRo.java

...smp/spi/examples/DomiSMPResourceExampleExtensionTest.java

.../smp/spi/examples/def/DomiSMPJsonResourceExampleTest.java

.../spi/examples/def/DomiSMPPropertyResourceExampleTest.java

...ropa/ec/smp/spi/examples/handler/AbstractHandlerTest.java

...p/spi/examples/handler/DomiSMPJSONHandlerExampleTest.java

...i/examples/handler/DomiSMPPropertyHandlerExampleTest.java

...mple/src/test/resources/examples/properties_ok.properties

.../eu/europa/ec/smp/spi/ExamplePayloadValidatorSpiImpl.java