[REFACTOR] payments sse endpoint (#1781)

* exclude sse from gzip

* refactor sse endpoint

* cleanup imports

lnbits/middleware.py

@@ -7,6 +7,7 @@ from fastapi.responses import HTMLResponse, JSONResponse
 from slowapi import _rate_limit_exceeded_handler
 from slowapi.errors import RateLimitExceeded
 from slowapi.middleware import SlowAPIMiddleware
+from starlette.middleware.gzip import GZipMiddleware
 from starlette.types import ASGIApp, Receive, Scope, Send
 
 from lnbits.core import core_app_extra
@@ -115,6 +116,18 @@ class InstalledExtensionMiddleware:
         )
 
 
+class CustomGZipMiddleware(GZipMiddleware):
+    def __init__(self, *args, exclude_paths=None, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.exclude_paths = exclude_paths or []
+
+    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
+        if "path" in scope and scope["path"] in self.exclude_paths:
+            await self.app(scope, receive, send)
+            return
+        await super().__call__(scope, receive, send)
+
+
 class ExtensionsRedirectMiddleware:
     # Extensions are allowed to specify redirect paths.
     # A call to a path outside the scope of the extension can be redirected to one of the extension's endpoints.