fix(dom-to-react): default props.children to undefined instead of null

[remarkablemark]

What is the motivation for this pull request?

fix(dom-to-react): default props.children to undefined instead of null

What is the current behavior?

props.children defaults to null. E.g., parse('<br>'):

{
  '$$typeof': Symbol(react.element),
  type: 'br',
  key: null,
  ref: null,
  props: { children: null },
  _owner: null,
  _store: {}
}

What is the new behavior?

props.children defaults to undefined

This ensures the parsed element is consistent with the React element <br >:

{
  '$$typeof': Symbol(react.element),
  type: 'br',
  key: null,
  ref: null,
  props: {},
  _owner: null,
  _store: {}
}

Checklist:

• Conventional Commits
• Tests
• Documentation

[codecov]

Codecov Report

Merging #1127 (a6978c3) into master (57571aa) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master     #1127   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            8         8           
  Lines          153       153           
  Branches        50        50           
=========================================
  Hits           153       153           

Files	Coverage Δ
src/dom-to-react.ts	100.00% <100.00%> (ø)

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[github-actions]

size-limit report 📦

Path	Size	Loading time (3g)	Running time (snapdragon)	Total time
dist/html-react-parser.min.js	10.2 KB (0%)	205 ms (0%)	26 ms (+104.93% 🔺)	230 ms

[remarkablemark]

Release:

• chore(master): release 5.0.1 #1128 (comment)