Exception when updating a product when optional fields are null

[medteck]

When I attempt to edit a product via the Sylius backoffice, I get an exception if:

• Description or Short Description is null: This is the error I get : {"result":"Argument 17 passed to BitBag\\SyliusVueStorefrontPlugin\\Document\\Product\\Details::__construct() must be of the type string, null given, called in \/home\/medteck\/Documents\/Projects\/Jaba\/jaba-sylius\/vendor\/bitbag\/vuestorefront-plugin\/src\/Sylius\/Transformer\/SyliusProduct\/ProductDetailsTransformer.php on line 50","code":500}

• Or Product has no media file uploaded: This is the error I get: {"result":"Call to a member function getPath() on bool","code":500}

• And sometimes, when the attribute "type" for media is null

[Codeweld]

Fixed by #102. Thank you @medteck for your input