feat(FloatingBubble): allow gap xy to be set separately (#13297)

[ALiangLiang]

期望如標題所述，這樣我就能貼近側邊設定離底部多高。

兼容 number 同時，新增 { x: number, y: number } 類型，採用此類型而不是數組的原因是與 v-model:offset 同類型較統一。

close #13297

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.69%. Comparing base (ec5b45b) to head (9b8655d).
Report is 77 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #13429      +/-   ##
==========================================
+ Coverage   89.60%   89.69%   +0.09%     
==========================================
  Files         257      257              
  Lines        7013     7026      +13     
  Branches     1736     1739       +3     
==========================================
+ Hits         6284     6302      +18     
+ Misses        384      380       -4     
+ Partials      345      344       -1     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[chenjiahan]

LGTM, thank you!