Add configurable sizing to Iconify input

[ruibaby]

What type of PR is this?

/area ui
/kind feature
/milestone 2.23.x

What this PR does / why we need it:

Add configurable sizing to Iconify input, example:

- $formkit: iconify
  sizing:
    enabled: true # default false
    default: '24px'
    presets:
      - 24px
      - 32px
      - 64px

Which issue(s) this PR fixes:

Fixes #8046

Does this PR introduce a user-facing change?

FormKit Iconify 支持设置尺寸参数，默认不再向用户显示尺寸设置选项

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.83%. Comparing base (42c374d) to head (2ac3eb4).
⚠️ Report is 454 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #8346      +/-   ##
============================================
+ Coverage     59.55%   60.83%   +1.27%     
- Complexity     3812     3999     +187     
============================================
  Files           677      698      +21     
  Lines         23248    23856     +608     
  Branches       1500     1555      +55     
============================================
+ Hits          13846    14513     +667     
+ Misses         8764     8613     -151     
- Partials        638      730      +92     

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[JohnNiang]

/lgtm

[f2c-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: JohnNiang

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• OWNERS [JohnNiang]

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