Improve user interaction with validation and processing buttons

Add `data-testid` attributes to the "Validate" and "Mark Processed" buttons in the DlcPage for improved testing and add a title to the "Validate" button.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 1e4433b5-47ab-464c-b663-fea2e53367dd
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/1e4433b5-47ab-464c-b663-fea2e53367dd/px42AkO

.replit

@@ -19,10 +19,6 @@ externalPort = 80
 localPort = 33873
 externalPort = 3003
 
-[[ports]]
-localPort = 37973
-externalPort = 4200
-
 [[ports]]
 localPort = 38343
 externalPort = 3000
@@ -31,6 +27,10 @@ externalPort = 3000
 localPort = 38451
 externalPort = 3002
 
+[[ports]]
+localPort = 41077
+externalPort = 5000
+
 [[ports]]
 localPort = 41343
 externalPort = 3001