Improve SSLConnection buffers handling (CVE-2022-2191)

**Jetty version(s)**
10+

**Description**
`SSLConnection`'s buffers utilization and their pooling should be reviewed.

**Fixes Security Advisory**
https://github.com/eclipse/jetty.project/security/advisories/GHSA-8mpp-f3f7-xc28
CVE-2022-2191