fix: handle special characters in select flag

[reubenmiller]

Fix a bug where the path provided by the --select flag would not handle paths with special characters such as @|#?*.

See tests for more details.

Resolves #340

Example

echo '{"with@at":"one","with#hash":"two","with|pipe":"three","with*star":"four","with?questionmark":"five"}' |
        c8y util show --select "with@at,with#hash,with|pipe,with\*star,with?questionmark" -o json

Now outputs the following (instead of {}):

{
  "with#hash": "two",
  "with*star": "four",
  "with?questionmark": "five",
  "with@at": "one",
  "with|pipe": "three"
}