feat: Customize HTTPClient by extending httpx.Client

[chyroc]

• Created a custom HTTPClient class that inherits from httpx.Client
• Overridden default parameters such as timeout configuration
• Adjusted connection pool settings for better performance and control

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 94.44444% with 2 lines in your changes missing coverage. Please review.

Project coverage is 75.55%. Comparing base (892443d) to head (d2ab5e2). Report is 25 commits behind head on main.

Files with missing lines	Patch %	Lines
cozepy/request.py	93.10%	2 Missing :warning:

@@            Coverage Diff             @@
##             main      #23      +/-   ##
==========================================
+ Coverage   74.91%   75.55%   +0.64%     
==========================================
  Files          24       24              
  Lines         845      859      +14     
==========================================
+ Hits          633      649      +16     
+ Misses        212      210       -2     

Flag	Coverage Δ
	75.55% <94.44%> (+0.64%)	:arrow_up:

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Files with missing lines	Coverage Δ
cozepy/__init__.py	100.00% <100.00%> (ø)
cozepy/config.py	100.00% <100.00%> (ø)
cozepy/coze.py	62.06% <100.00%> (ø)
cozepy/request.py	80.00% <93.10%> (+7.27%)	:arrow_up: