optimize rewrite regex

[johnlanni]

Ⅰ. Describe what this PR did

Before optimization, when the user adds the following annotation in ingress and the path contains regular expression characters (.+*?()|[]{}^$), higress will change the path type to regular expression (for compatible with the mechanism introduced by nginx).

nginx.ingress.kubernetes.io/rewrite-target: ''

Ⅱ. Does this pull request fix one issue?

Ⅲ. Why don't you add test cases (unit test/integration test)?

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (90f89cf) 38.14% compared to head (d4a1644) 38.14%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #801   +/-   ##
=======================================
  Coverage   38.14%   38.14%           
=======================================
  Files          61       61           
  Lines       10342    10342           
=======================================
  Hits         3945     3945           
  Misses       6098     6098           
  Partials      299      299           

Files	Coverage Δ
pkg/ingress/kube/annotations/annotations.go	31.63% <100.00%> (ø)