Fix: islington_gov_uk - Page structure changed

[ReneNulschDE]

This PR is to fix #3040.

Breaking change: Postcode is a new configuration requirement.

Tasks:

• Page structure changed
• Postcode is required now

Tests:

Testing source islington_gov_uk ...
  found 1 entries for Test_001
    2024-11-20 : Mixed dry recycling
  found 3 entries for Test_002
    2024-11-21 : Non-recyclable rubbish
    2024-11-21 : Mixed dry recycling
    2024-11-21 : Food waste recycling
  found 3 entries for Test_003
    2024-11-21 : Non-recyclable rubbish
    2024-11-21 : Mixed dry recycling
    2024-11-21 : Food waste recycling

[5ila5]

Thanks for your contribution