Update testtool arguments

Update testtool arguments

1. Remove edit-content argument. Instead of using node config template
in form of file node config will be created, modified by corresponding
Java models and than converted to request body string with GSON.
2. Split auth argument to controller-auth-username,
controller-auth-password. Add default value(admin) for them.
3. Split controller-destination argument to controller-ip,
controller-port.

JIRA: NETCONF-758
Change-Id: Iccf19c9482727b88d3f21a85008d13f554a8da08
Signed-off-by: Illia <illia.ihushev@pantheon.tech>