Some fixes in parsing flags and add example with cobra usage

[name212]

Fix flags parsing:

• copy of flag set is not deep, thus we have problems is call multiple parsers with InitFlags. Now we are using internal flag set for parsing flags in parser, but add another fake flag set to passed flag set into InitFlags, for output help and prevent unknown flags error during parsing paret flags
• filepath.Abs does not resolve ~, we were fixed it

Add parser to Flags and ExtractConfig method, it improve dx because we can init flags during initialize command and pass only Flags to handler

If ssh connection config set ForceUseSSHAgent force no init new agent in cli-ssh

Also add check that hosts were set in DefaultSSHProvider

AskPassword add new line after prompt. We were fix it.

Add example with working library with cobra packages.

Some fixes in README