[type: feat] send alarm message when gateway global error happen

[tomsun28]

• send alarm message when gateway global error happen

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

Attention: 9 lines in your changes are missing coverage. Please review.

Comparison is base (da9e6a6) 61.56% compared to head (09464f4) 61.53%.

Files	Patch %	Lines
...g/apache/shenyu/plugin/base/alert/AlarmSender.java	0.00%	8 Missing ⚠️
.../apache/shenyu/web/handler/GlobalErrorHandler.java	88.88%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #5382      +/-   ##
============================================
- Coverage     61.56%   61.53%   -0.03%     
+ Complexity     8521     8519       -2     
============================================
  Files          1236     1236              
  Lines         37314    37325      +11     
  Branches       3593     3594       +1     
============================================
- Hits          22973    22969       -4     
- Misses        12257    12274      +17     
+ Partials       2084     2082       -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.