client/remote: add support to specify port number

this adds the ability to add port numbers in the backup repo spec
as well as remotes, so that user that are behind a
NAT/Firewall/Reverse proxy can still use it

also adds some explanation and examples to the docs to make it clearer
for h2 client i left the localhost:8007 part, since it is not
configurable where we bind to

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/bin/proxmox_backup_client/mount.rs

@@ -101,7 +101,7 @@ async fn mount_do(param: Value, pipe: Option<RawFd>) -> Result<Value, Error> {
     let repo = extract_repository_from_value(&param)?;
     let archive_name = tools::required_string_param(&param, "archive-name")?;
     let target = tools::required_string_param(&param, "target")?;
-    let client = connect(repo.host(), repo.user())?;
+    let client = connect(repo.host(), repo.port(), repo.user())?;
 
     record_repository(&repo);