Move http_header_entry_t to common as http_header_t

http_header_t should be treated as a common struct with helpers.

Issue: 50189
diff --git a/src/common/http.c b/src/common/http.c
index 73e03c8..ffc1217 100644
--- a/src/common/http.c
+++ b/src/common/http.c
@@ -411,3 +411,10 @@
 	dst->query = xstrdup(src->query);
 	dst->fragment = xstrdup(src->fragment);
 }
+
+extern void free_http_header(http_header_t *header)
+{
+	xfree(header->name);
+	xfree(header->value);
+	xfree(header);
+}
diff --git a/src/common/http.h b/src/common/http.h
index 8705a2a..cae5158 100644
--- a/src/common/http.h
+++ b/src/common/http.h
@@ -209,4 +209,13 @@
 /* Copy all members in URL */
 extern void url_copy_members(url_t *dst, const url_t *src);
 
+/* HTTP header */
+typedef struct {
+	char *name;
+	char *value;
+} http_header_t;
+
+/* Free http header and contents */
+extern void free_http_header(http_header_t *header);
+
 #endif /* SLURM_HTTP_H */
diff --git a/src/slurmrestd/http.c b/src/slurmrestd/http.c
index 6083834..da98f2a 100644
--- a/src/slurmrestd/http.c
+++ b/src/slurmrestd/http.c
@@ -124,13 +124,6 @@
 	return ESLURM_HTTP_UNSUPPORTED_VERSION;
 }
 
-extern void free_http_header(http_header_entry_t *header)
-{
-	xfree(header->name);
-	xfree(header->value);
-	xfree(header);
-}
-
 static void _free_http_header(void *header)
 {
 	free_http_header(header);
diff --git a/src/slurmrestd/http.h b/src/slurmrestd/http.h
index c08b371..3f094a8 100644
--- a/src/slurmrestd/http.h
+++ b/src/slurmrestd/http.h
@@ -78,11 +78,7 @@
 	const char *body_encoding; /* body encoding type or NULL */
 } on_http_request_args_t;
 
-typedef struct {
-	char *name;
-	char *value;
-} http_header_entry_t;
-extern void free_http_header(http_header_entry_t *);
+typedef http_header_t http_header_entry_t;
 
 /* find http header from header list
  * IN headers List of http_header_entry_t