Binary parameter handling for GeoDjango

[eduzen]

Description

hey folks, this is my very first PR in the django-commons. I did this because I faced the issue myself in one project that I'm working on. I don't know how I can test this in that project. So I will wait for some of you to tell me how I can do that... but in the meantime this is the fix for the SQL Explain functionality for GeoDjango queries with binary parameters.

Fixes #423

SQL Explain feature throws a 500 error when used with GeoDjango queries containing binary parameters. This affects any query using PostGIS functions like ST_GeomFromEWKB(), ST_Distance_Sphere(), etc.
I'm trying to create a robust binary parameter handling system:

1. Enhanced Parameter Encoding (tracking.py)

• Detects binary data (bytes, bytearray) during parameter logging
• Encodes binary data as base64 with a special marker: {"djdt_binary": "base64_data"}
• Preserves exact binary integrity through JSON serialization

2. Parameter Reconstruction (forms.py)

• Added _reconstruct_params() function to decode stored parameters
• Recursively handles nested structures (lists, dicts) containing binary data
• Restores original binary data from base64 encoding

3. Updated SQL Operations

• Modified select(), explain(), and profile() methods to use parameter reconstruction
• Added helper method _get_query_params() to eliminate code duplication

Checklist:

• I have added the relevant tests for this change.
• I have added an item to the Pending section of docs/changes.rst.

[tim-schilling]

Do you think this would be improved by making use of the json.loads(..., cls) argument?

[eduzen]

If I understand you correctly, @tim-schilling, you're suggesting that we create our own DebugToolbarJSONDecoder and use it like this: json.loads(query["params"], cls=DebugToolbarJSONDecoder), so we can encapsulate all the base64 logic inside of _reconstruct_params in custom JSON decoder class?

[eduzen]

@tim-schilling I added some commits following what you were pointing out, let me know what do you think!