Draft: Classify using session prefix
This MR adds changes such that the HTTP Router:
- Finds the cookie value of cookie that starts with
_gitlab_session
, if it exists. - If so, using regex, strips out the prefix of the session cooking starting with
cell-
, eg:cell-1
. - And then passes this value onto Topology Service to classify.
If such a cookie is not found, it falls back to classifying using FirstCell