Enhance Node Version RisuAI Backend Server File I/O Performance (#485)

# PR Checklist
- [ ] Did you check if it works normally in all models? *ignore this
when it dosen't uses models*
- [x] Did you check if it works normally in all of web, local and node
hosted versions? if it dosen't, did you blocked it in those versions?
- [ ] Did you added a type def?

# Description
노드리스의 /api/write와 /api/read에서 base64를 제거해 파일 용량 과 I/O에 필요한 연산량을 줄였습니다.
Removed base64 from /api/write and /api/read on node version rise to
reduce file size and the amount of computation required for I/O.

src/ts/storage/nodeStorage.ts

@@ -9,11 +9,9 @@ export class NodeStorage{
         await this.checkAuth()
         const da = await fetch('/api/write', {
             method: "POST",
-            body: JSON.stringify({
-                content: Buffer.from(value).toString('base64')
-            }),
+            body: value,
             headers: {
-                'content-type': 'application/json',
+                'content-type': 'application/octet-stream',
                 'file-path': Buffer.from(key, 'utf-8').toString('hex'),
                 'risu-auth': auth
             }
@@ -35,17 +33,15 @@ export class NodeStorage{
                 'risu-auth': auth
             }
         })
-        const data = await da.json()
         if(da.status < 200 || da.status >= 300){
             throw "getItem Error"
         }
-        if(data.error){
-            throw data.error
-        }
-        if(data.content === null){
+
+        const data = Buffer.from(await da.arrayBuffer())
+        if (data.length == 0){
             return null
         }
-        return Buffer.from(data.content, 'base64')
+        return data
     }
     async keys():Promise<string[]>{
         await this.checkAuth()