fix: encode URI parameter to proxy URI

Closes #326

src/app/modules/hebis/daia-data.provider.spec.ts

@@ -115,7 +115,7 @@ describe('DaiaDataProvider', () => {
       };
 
       expect(daiaDataProvider.getHoldingLink(holding)).toEqual(
-        `${proxyUrl}${available.href}`,
+        `${proxyUrl}${encodeURIComponent(available.href as string)}`,
       );
     });
   });

src/app/modules/hebis/daia-data.provider.ts

@@ -206,7 +206,7 @@ export class DaiaDataProvider {
       return resourceLink;
     }
 
-    return `${this.hebisProxyUrl}${resourceLink}`;
+    return `${this.hebisProxyUrl}${encodeURIComponent(resourceLink)}`;
   }
 
   holdingHasStatus(available: DaiaService[]): boolean {