test: move greenprint and redprint functions to shared_lib.sh

Since we're sharing functions between test scripts, move greenprint(),
the most rewritten function in the history of the project, to
shared_lib.sh and source it everywhere.

test/cases/api/common/aws.sh

@@ -1,4 +1,5 @@
 #!/usr/bin/bash
+source /usr/libexec/tests/osbuild-composer/shared_lib.sh
 
 function installClient() {
   if ! hash aws; then

test/cases/api/common/s3.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/bash
 
+source /usr/libexec/tests/osbuild-composer/shared_lib.sh
+
 function createReqFileEdge() {
   cat > "$REQUEST_FILE" << EOF
 {