http2: implement maxSessionMemory

The maxSessionMemory is a cap for the amount of memory an
Http2Session is permitted to consume. If exceeded, new
`Http2Stream` sessions will be rejected with an
`ENHANCE_YOUR_CALM` error and existing `Http2Stream`
instances that are still receiving headers will be
terminated with an `ENHANCE_YOUR_CALM` error.

PR-URL: https://github.com/nodejs/node/pull/17967
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Matteo Collina <[email protected]>
diff --git a/src/node_http2_state.h b/src/node_http2_state.h
index ef8696c..af0740c 100644
--- a/src/node_http2_state.h
+++ b/src/node_http2_state.h
@@ -50,6 +50,7 @@
     IDX_OPTIONS_MAX_HEADER_LIST_PAIRS,
     IDX_OPTIONS_MAX_OUTSTANDING_PINGS,
     IDX_OPTIONS_MAX_OUTSTANDING_SETTINGS,
+    IDX_OPTIONS_MAX_SESSION_MEMORY,
     IDX_OPTIONS_FLAGS
   };