Modules: renaming vars to rawVariables to better reflect purpose.

In 434f20c29f4c, obj.vars was introduced.  obj.vars is almost identical
to obj.variables except a value of the Buffer type is returned.

Since most nginx variables are valid strings, it is preferable to
leave both variants.

To avoid confusion rawVariables name is used for Buffer variables.
diff --git a/nginx/ngx_http_js_module.c b/nginx/ngx_http_js_module.c
index 437f6be..a576fab 100644
--- a/nginx/ngx_http_js_module.c
+++ b/nginx/ngx_http_js_module.c
@@ -406,7 +406,7 @@
 
     {
         .flags = NJS_EXTERN_OBJECT,
-        .name.string = njs_str("vars"),
+        .name.string = njs_str("rawVariables"),
         .u.object = {
             .writable = 1,
             .prop_handler = ngx_http_js_ext_variables,
diff --git a/nginx/ngx_stream_js_module.c b/nginx/ngx_stream_js_module.c
index 2900ac5..e53b624 100644
--- a/nginx/ngx_stream_js_module.c
+++ b/nginx/ngx_stream_js_module.c
@@ -245,7 +245,7 @@
 
     {
         .flags = NJS_EXTERN_OBJECT,
-        .name.string = njs_str("vars"),
+        .name.string = njs_str("rawVariables"),
         .u.object = {
             .writable = 1,
             .prop_handler = ngx_stream_js_ext_variables,