fix: correct MD5 calculation for InputStream and File

[cuishuang]

What is the purpose of the change?

Fix incorrect MD5 calculation in Bytes.getMD5(InputStream) and Bytes.getMD5(File).

The previous implementation used InputStream.available() to detect EOF and passed the entire buffer to MessageDigest.update(). For a final partial read, zero-filled bytes were included in the digest. Streams that report available() == 0 while still containing readable data were also skipped.

This change reads until read() returns -1 and updates the digest with only the bytes actually read.

GitHub issue: #16451

Checklist

• Make sure there is a GitHub_issue field for the change.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Make sure gitHub actions can pass. Why the workflow is failing and how to fix it?

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.55%. Comparing base (dab47b7) to head (c46bbd1).

Additional details and impacted files

@@             Coverage Diff              @@
##                3.3   #16452      +/-   ##
============================================
- Coverage     60.91%   60.55%   -0.37%     
- Complexity       15    10255   +10240     
============================================
  Files          1953     1953              
  Lines         89271    89265       -6     
  Branches      13473    13471       -2     
============================================
- Hits          54383    54056     -327     
- Misses        29309    29584     +275     
- Partials       5579     5625      +46     

Flag	Coverage Δ
integration-tests-java21	?
integration-tests-java8	?
samples-tests-java21	32.16% <0.00%> (+<0.01%)	⬆️
samples-tests-java8	29.84% <0.00%> (+<0.01%)	⬆️
unit-tests-java11	59.18% <100.00%> (+0.02%)	⬆️
unit-tests-java17	58.65% <100.00%> (-0.01%)	⬇️
unit-tests-java21	58.62% <100.00%> (-0.03%)	⬇️
unit-tests-java25	58.58% <100.00%> (-0.03%)	⬇️
unit-tests-java8	59.18% <100.00%> (-0.01%)	⬇️

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