The threee tags `<name>`, `</name>` and `<command>` were frequently used
with a leading space that this removes. The reason this habbit is so
widespread in testcases is probably that they have been copy and pasted.
Hence, fixing them all now might curb this practice from now on.
Closes#12028
- add an `id` long to Curl_easy, -1 on init
- once added to a multi (or its own multi), it gets
a non-negative number assigned by the connection cache
- `id` is unique among all transfers using the same
cache until reaching LONG_MAX where it will wrap
around. So, not unique eternally.
- CURLINFO_CONN_ID returns the connection id attached to
data or, if none present, data->state.lastconnect_id
- variables and type declared in tool for write out
Closes#11185
