Transfer Panel Details Without an Extra Layer of JSON Encoding (#14)

**Rationale:**

This made it harder to snoop on the traffic in the network monitor because it was encoded as a string.

**Changes:**

- Backend now accepts & provides the panel data as a JSON object rather than as a string
- Backend now supports compression
- Minor improvements to error handling
- Some panel structures were getting saved in the JSON when they weren't supposed to be (now this no longer happens)

Reviewed-on: #14
Co-authored-by: Sergey Savelyev <sergeysav.nn@gmail.com>
Co-committed-by: Sergey Savelyev <sergeysav.nn@gmail.com>

frontend/src/components/CommandSender.vue

@@ -4,7 +4,7 @@ import { ref } from 'vue';
 import CommandParameter from '@/components/CommandParameter.vue';
 import FlexDivider from '@/components/FlexDivider.vue';
 import type { DynamicDataType } from '@/composables/dynamic.ts';
-import { toJsonString } from '@/composables/json.ts';
+import { parseJsonString, toJsonString } from '@/composables/json.ts';
 
 const props = defineProps<{
     command: CommandDefinition | null;
@@ -30,10 +30,11 @@ async function sendCommand() {
         },
         body: toJsonString(params),
     });
+    const text_response = await response.text();
     if (response.ok) {
-        result.value = await response.json();
+        result.value = parseJsonString(text_response);
     } else {
-        result.value = await response.text();
+        result.value = text_response;
     }
     busy.value = false;
 }