Move it to its own header.
Get rid of SshConnection and SshConnectionManager,
as they are not used anymore.
Change-Id: I52fe20d7816ea57e7a7158ab2ae9565d50a76e21
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>