[GSProcessing] Fix isinstance check for numerical features

[thvasilo]

Issue #, if available:

Description of changes:

• Fixes corner case where a feature value might not be one of int/float (we don't cast Parquet input types), replacing with the more general numbers.Number.

Example of how to trigger a failure, as observed by a customer:

>>> import numbers
>>> import decimal
>>> dn = decimal.Decimal(5)
>>> intnum = 5
>>> isinstance(intnum, (float, int))
True
>>> isinstance(dn, (float, int))
False
>>> isinstance(dn, numbers.Number)
True

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[jalencato]

LGTM, but a small comment.

[thvasilo]

Made a small change to avoid code repetition and to implement @classicsong suggestion

@jalencato can you take a second look? The last commit pulls out the write_feature function and shares the implementation between nodes and edges.