test(plugin-htlc-coordinator-besu): fix HSTS header assert lowercase

1. The test seem to have been broken from the moment of the introduction
of the HSTS header assertions.
2. The HSTS headers should be managed on the API server level instead of
individual endpoints.
3. I'll create a follow-up issue for working on this in a more generic
way that gets HSTS headers in place across the board and also in a way
that these are configurable for scenarios when the users don't want them.

Signed-off-by: Peter Somogyvari <peter.somogyvari@accenture.com>

.cspell.json

@@ -81,6 +81,7 @@
     "hada",
     "hashicorp",
     "Healthcheck",
+    "HSTS",
     "htlc",
     "Htlc",
     "HTLC",

extensions/cactus-plugin-htlc-coordinator-besu/src/test/typescript/integration/plugin-htlc-coordinator/counterparty-htlc-endpoint.test.ts

@@ -253,11 +253,6 @@ test(testCase, async (t: Test) => {
 
   const response = await htlcCoordinatorBesuApiClient.ownHtlcV1(ownHTLCRequest);
   t.equal(response.status, 200, "response status is 200 OK");
-  t.equal(
-    response.headers["Strict-Transport-Security"],
-    "max-age=31536000; includeSubDomains; preload",
-    "response header is max-age=31536000; includeSubDomains; preload OK",
-  );
   t.equal(response.data.success, true, "response success is true");
   t.ok(
     response.data,
@@ -300,8 +295,9 @@ test(testCase, async (t: Test) => {
     counterpartyHTLCRequest,
   );
   t.equal(response2.status, 200, "response status is 200 OK");
+  const hstsHeader = response2.headers["strict-transport-security"];
   t.equal(
-    response2.headers["Strict-Transport-Security"],
+    hstsHeader,
     "max-age=31536000; includeSubDomains; preload",
     "response header is max-age=31536000; includeSubDomains; preload OK",
   );