Ignore empty cast names

[Falke-Design]

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• My changes respect the Kodi add-on development rules
• I have read the CONTRIBUTING document.
• I made sure there wasn't another Pull Request opened for the same update/change
• I have successfully tested my changes locally

Types of changes

• New feature (non-breaking change which adds functionality)
• Feature change (non-breaking change which changes behaviour of an existing functionality)
• Improvement (non-breaking change which improves functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactor (non-breaking performance or readability improvements)

Description

Fixes: #1655

"Error TypeError: Actor: name property must not be empty" occurs.

This happens if the Cast has some empty entries.
For example the movie Misfit:

{
   "Title":"Misfit",
   "Cast":[
      "Selina Mour",
      "Lion Wasczyk",
      "Lisa-Marie Koroll",
      "Jonathan Elias Weiske",
      "Vivien Wulf",
      "Meriel Hinsching",
      "",
      "Moritz Schirdewahn",
      "Simon Will",
      "Sylvie Meis"
   ],
...

[CastagnaIT]

not do this here, wrapper must not change data
there is to check the json path response to verify why/when there is a empty value and act on the right place

[Falke-Design]

Makes sense, changed

[Falke-Design]

Attention while testing: the cache needs to be cleared else the info data will be not parsed again. And then the error will still occur

[CastagnaIT]

take a look on my new PR solution opened, and take a look at the differences,
also take in account that the "person" list is not used by "cast" only but from each REFERENCE_MAPPINGS value,
so the change is more small and not require specifics additional for loop and data replacing as done here