1451 avoid fading assign sources listing when advanced inventory manage stock being changed

[VitaliyBoyko]

Fixed Issues (if relevant)

1. Avoid fading assign sources listing when advanced inventory manage stock being changed #1451:
   Avoid fading assign sources listing when advanced inventory manage stock being changed

Steps to reproduce

1. Open product form
2. Click on "advanced inventory"
3. Set manage stock to "No" and click "Done"

Expected result

Assign sources dynamic rows should be visible, inputs related to stock should be disabled.

Actual result

assign sources dynamic rows will fade.

[smoskaluk]

@VitaliyBoyko Hi Vitaliy, may you please recheck your PR

1. Problem - in single stock mode on the product page in admin present "Sources' tab
2. Problem - after creating custom source and then creating simple product and assign to default and custom sources - after save product get 'Mange stock' = No in 'Advanced inventory' (despite that 'Use config settings' is checked)
   

[VitaliyBoyko]

Hi @smoskaluk
All mentioned issues have been fixed. Thank you!

[smoskaluk]

Hi @VitaliyBoyko!
in single stock mode on the product page in admin "Sources' tab is present again

[VitaliyBoyko]

Thanks @smoskaluk
Gonna check it.

[VitaliyBoyko]

@smoskaluk I've hidden sources tab in single stock mode instead of hiding source button and dynamic rows.