fix(engine): fix mapping issue when multiple reason codes are available

[shunguoy]

sync dev branch dev-1674 with dev-1731

• Rule bug: target_spacinf_sufficient

This PR is related to the following issue(s):

#1731

Testing reference:

1. select "WCAG_2_2" ruleset.
2. run the following test case: test/v2/checker/accessibility/rules/target_spacing_sufficient_ruleunit/element_target.html
3. You should see the level of the following message is changed from "Recommendation" to "Violation":
   'Undersized target "button" does not have sufficient spacing of 12 CSS pixels from another target "button"'

I have conducted the following for this PR:

• I validated this code in Chrome and FF
• I validated this fix in my local env
• I provided details for testing
• This PR has been reviewed and is ready for test
• I understand that the title of this PR will be used for the next release notes.