Change separator for metadata and tags (#82)

This is required to allow http headers with values like 
`x-p-meta-podlabels:app=goapp,hash=64f724hua4gs,make=cc`

Author: trueleo

server/src/handlers/event.rs

@@ -33,7 +33,7 @@ use crate::utils::{self, merge};
 
 const PREFIX_TAGS: &str = "x-p-tags-";
 const PREFIX_META: &str = "x-p-meta-";
-const SEPARATOR: char = ',';
+const SEPARATOR: char = '^';
 
 pub async fn query(_req: HttpRequest, json: web::Json<Value>) -> HttpResponse {
     let json = json.into_inner();

server/src/utils.rs

@@ -90,7 +90,7 @@ pub mod header_parsing {
             return Err(ParseHeaderError::MaxHeadersLimitExceeded);
         }
 
-        Ok(labels.join(","))
+        Ok(labels.join(&kv_separator.to_string()))
     }
 
     #[derive(Debug, thiserror::Error)]