Implement web-based user management / admin setup. (#8)

Implement Admin Settings dialog for user management and toggling the public server flag, not needing CLI for maintenance anymore.

frontend/src/repositories/Client.ts

@@ -1,4 +1,20 @@
 class ClientClass {
+  async get(url: string): Promise<any> {
+    const res = await fetch(url, {
+      method: 'GET',
+      headers: {
+        accept: 'application/json'
+      }
+    })
+    let msg
+    try {
+      msg = await res.json()
+    } catch (e) {
+      throw new SimpleError(res.status, `🛑 ${res.status} ${res.statusText}`)
+    }
+    if ('error' in msg) throw new SimpleError(msg.error.code, msg.error.message)
+    return msg
+  }
   async post(url: string, data?: Record<string, any>): Promise<any> {
     const res = await fetch(url, {
       method: 'POST',
@@ -17,6 +33,40 @@ class ClientClass {
     if ('error' in msg) throw new SimpleError(msg.error.code, msg.error.message)
     return msg
   }
+  async put(url: string, data?: Record<string, any>): Promise<any> {
+    const res = await fetch(url, {
+      method: 'PUT',
+      headers: {
+        accept: 'application/json',
+        'content-type': 'application/json'
+      },
+      body: data !== undefined ? JSON.stringify(data) : undefined
+    })
+    let msg
+    try {
+      msg = await res.json()
+    } catch (e) {
+      throw new SimpleError(res.status, `🛑 ${res.status} ${res.statusText}`)
+    }
+    if ('error' in msg) throw new SimpleError(msg.error.code, msg.error.message)
+    return msg
+  }
+  async delete(url: string): Promise<any> {
+    const res = await fetch(url, {
+      method: 'DELETE',
+      headers: {
+        accept: 'application/json'
+      }
+    })
+    let msg
+    try {
+      msg = await res.json()
+    } catch (e) {
+      throw new SimpleError(res.status, `🛑 ${res.status} ${res.statusText}`)
+    }
+    if ('error' in msg) throw new SimpleError(msg.error.code, msg.error.message)
+    return msg
+  }
 }
 
 export const Client = new ClientClass()