Use install instead of installmissing if Chocolatey >= 0.9.8.24

X-ref: #13980

This also adds a chocolatey.chocolatey_version function and does some
DRY cleanup so that the error message and exception are raised in
_find_chocolatey() instead of in 6-8 different places.
Merge pull request #14358 from terminalmage/issue13980

Use install instead of installmissing if Chocolatey >= 0.9.8.24