fix: use Database Lab client host if accessHost is not specified, error reporting (#144)

Description

• use Database Lab client host after clone creation in case the localhost is given as accessHost at Database Lab config.
• process connection errors properly: send message as well, not only to logs

Related issue

#144 (closed)

Checklist

• the MR description has been reviewed
• this MR contains text changes and they have been reviewed OR there are no texts changes
• this MR contains GUI/CLI changes and they have been reviewed OR there are no GUI/CLI changes
• this MR contains API changes and they have been reviewed OR there are no API changes

Closes #144 (closed)