Replace abort() with raise SanicException

This is for compatibility with newly-released Sanic 21.12 which removed the deprecated `abort()` in sanic-org/sanic#2306. Before that, it was a simple wrapper around `raise SanicException` (https://github.com/sanic-org/sanic/blob/523db190a732177eda5a641768667173ba2e2452/sanic/exceptions.py#L262-L265), so this change makes it explicit and removes the dependency on `abort()`.

strawberry/sanic/views.py

@@ -1,7 +1,7 @@
 import json
 from typing import Any
 
-from sanic.exceptions import ServerError, abort
+from sanic.exceptions import SanicException, ServerError
 from sanic.request import Request
 from sanic.response import HTTPResponse, html
 from sanic.views import HTTPMethodView
@@ -57,7 +57,7 @@ def process_result(self, result: ExecutionResult) -> GraphQLHTTPResponse:
 
     async def get(self, request: Request) -> HTTPResponse:
         if not self.graphiql:
-            abort(404)
+            raise SanicException(status_code=404)
 
         template = render_graphiql_page()
         return self.render_template(template=template)
@@ -101,5 +101,5 @@ def parse_body(self, request: Request) -> dict:
             try:
                 return replace_placeholders_with_files(operations, files_map, files)
             except KeyError:
-                abort(400, "File(s) missing in form data")
+                raise SanicException(status_code=400, message="File(s) missing in form data")
         return request.json