Add --extended option to watchdog:show-one command

[gitressa]

Is your feature request related to a problem? Please describe.
drush watchdog:show --extended works well if you want to see the entire log message, but it can become quite a wall of text.

Describe the solution you'd like
It would be great to be able to get the full message of a single entry by also adding the --extended option to watchdog:show-one like this:

$ drush watchdog:show-one 310 --extended

[weitzman]

Now show-one is always extended. No option needed.