feat(theme:modal): add size support percentage

[cipchk]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/ng-alain/delon/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Application (the showcase website) / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[ng-alain-bot]

Preview is ready!

[codecov]

Codecov Report

Merging #1626 (809500d) into master (a171d50) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head 809500d differs from pull request most recent head 17c279c. Consider uploading reports for the commit 17c279c to get more accurate results

@@            Coverage Diff             @@
##           master    #1626      +/-   ##
==========================================
+ Coverage   95.56%   95.57%   +0.01%     
==========================================
  Files         277      277              
  Lines        8604     8605       +1     
  Branches     1681     1682       +1     
==========================================
+ Hits         8222     8224       +2     
  Misses        317      317              
+ Partials       65       64       -1     

Impacted Files	Coverage Δ
packages/theme/src/services/modal/modal.helper.ts	82.14% <100.00%> (+2.14%)	⬆️