[oozie] Validity check of workflow/action name does not match workflow specification

The Oozie workflow specification states that identifiers need to match the pattern "([a-zA-Z_]([\-_a-zA-Z0-9])*)

)", however single letter identifiers can not be created in Hue due to error "Enter a valid value: combination of 2 - 40 letters and digits starting by a letter".

Relatedly, when importing a workflow XML Hue does not check the validity of identifiers and will allow invalid names such as "1" to be saved.

Validity checks should be consistent across all ways a workflow/action can be created in Hue, and also consistent with the workflow specification.