feat: maven plugin protoSourceRoot参数支持读取文件夹

[Hisoka-X]

trpc-maven-plugin 在 protoSourceRoot 文件夹下没有proto文件，而存在多个子文件夹的场景会报错。此PR确保子文件夹下的proto文件也能正常被解析。

[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[Hisoka-X]

I have read the CLA Document and I hereby sign the CLA

[Hisoka-X]

cc @wardseptember

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 69.93529%. Comparing base (9dca999) to head (c1f5a14).

Additional details and impacted files

@@                  Coverage Diff                  @@
##                master        #104         +/-   ##
=====================================================
- Coverage     69.98776%   69.93529%   -0.05247%     
+ Complexity        4260        4256          -4     
=====================================================
  Files              437         437                 
  Lines            17153       17153                 
  Branches          1733        1733                 
=====================================================
- Hits             12005       11996          -9     
- Misses            4036        4044          +8     
- Partials          1112        1113          +1     

see 5 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.