[type:refactor] add domain test and polish pom

[moremind]

Make sure that:

• You have read the contribution guidelines.
• You submit test cases (unit or integration tests) that back your changes.
• Your local test passed ./mvnw clean install -Dmaven.javadoc.skip=true.

[codecov-commenter]

Codecov Report

Merging #4803 (5f1b8c3) into master (1b08ed0) will decrease coverage by 0.11%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #4803      +/-   ##
============================================
- Coverage     64.60%   64.49%   -0.11%     
+ Complexity     8171     8167       -4     
============================================
  Files          1147     1147              
  Lines         33773    33761      -12     
  Branches       3014     3010       -4     
============================================
- Hits          21818    21775      -43     
- Misses        10231    10265      +34     
+ Partials       1724     1721       -3     

Impacted Files	Coverage Δ
...ava/org/apache/shenyu/common/enums/PluginEnum.java	100.00% <ø> (ø)

... and 19 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more