fix: #918 update Barnsley parser to fix combined bin

[ezramorris]

Fixes #918

Barnsley parser was correctly splitting bins that appeared on "upcoming collections" but not "next collection". This change refactors the code to re-use the splitting logic in both places.

Also, an enhancement is added to ensure that bins are not added twice.

Output before change (as of today):

{
    "bins": [
        {
            "type": "Brown, Green bin",
            "collectionDate": "22/10/2024"
        },
        {
            "type": "Grey bin",
            "collectionDate": "29/10/2024"
        },
        {
            "type": "Blue bin",
            "collectionDate": "05/11/2024"
        },
        {
            "type": "Green bin",
            "collectionDate": "05/11/2024"
        },
        {
            "type": "Grey bin",
            "collectionDate": "12/11/2024"
        }
    ]
}

Output after change:

{
    "bins": [
        {
            "type": "Brown bin",
            "collectionDate": "22/10/2024"
        },
        {
            "type": "Green bin",
            "collectionDate": "22/10/2024"
        },
        {
            "type": "Grey bin",
            "collectionDate": "29/10/2024"
        },
        {
            "type": "Blue bin",
            "collectionDate": "05/11/2024"
        }
    ]
}

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.23%. Comparing base (4f93c5a) to head (f9c7e79).
Report is 8 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #921   +/-   ##
=======================================
  Coverage   97.23%   97.23%           
=======================================
  Files           4        4           
  Lines         253      253           
=======================================
  Hits          246      246           
  Misses          7        7           

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[ezramorris]

Updated title