detect/transform: Add case-change transform constants

Add the constants for the to_lowercase and to_uppercase transforms

Issue: 6439

src/detect-engine-register.h

@@ -325,6 +325,8 @@ enum DetectKeywordId {
     DETECT_TRANSFORM_PCREXFORM,
     DETECT_TRANSFORM_URL_DECODE,
     DETECT_TRANSFORM_XOR,
+    DETECT_TRANSFORM_TOLOWER,
+    DETECT_TRANSFORM_TOUPPER,
 
     DETECT_AL_IKE_EXCH_TYPE,
     DETECT_AL_IKE_SPI_INITIATOR,