- Change the swsbounce keyword to override the part number on a
subsequent request to the previous part number + 1.
Note the previous part number in this case is the part number that
was returned as a response to the previous request and contained
the swsbounce keyword.
Prior to this change swsbounce incremented the part number of the
subsequent request instead of overriding it, and did so in a more
limited fashion that prevented chaining swsbounce in multiple responses.
For example, if the test makes a request that causes the sws server to
return `<data>` as a response and that response contains `swsbounce`
then for the next response the sws server returns `<data1>`. If
`<data1>` also contains `swsbounce` then for the next response the sws
server now returns `<data2>` instead of the requested part.
Fixes https://github.com/curl/curl/discussions/16074
Closes https://github.com/curl/curl/pull/16085
