perf: svg cloning optimized using deep clone

[jagermesh]

Optimize cloning of SVG elements

Description

Instead of cloning each child SVG element (which in my case is around 200) we can use cloneNode(true) to use deep clone mode

Motivation and Context

Converting DIV with SVG inside taking around 20 second in Safari and around 15 in Chrome

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x ] Enhancement (changes that improvement of current feature or performance)
• [ ] Refactoring (changes that neither fixes a bug nor adds a feature)
• [ ] Test Case (changes that add missing tests or correct existing tests)
• [ ] Code style optimization (changes that do not affect the meaning of the code)
• [ ] Docs (changes that only update documentation)
• [ ] Chore (changes that don't modify src or test files)

Self Check before Merge

• [x ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[vivcat[bot]]

👋 @jagermesh

💖 Thanks for opening this pull request! 💖

Please follow the contributing guidelines. And we use semantic commit messages to streamline the release process.

Examples of commit messages with semantic prefixes:

• fix: don't overwrite prevent_default if default wasn't prevented
• feat: add graph.scale() method
• docs: graph.getShortestPath is now available

Things that will help get your PR across the finish line:

• Follow the TypeScript coding style.
• Run npm run lint locally to catch formatting errors earlier.
• Document any user-facing changes you've made.
• Include tests when adding/changing behavior.
• Include screenshots and animated GIFs whenever possible.

We get a lot of pull requests on this repo, so please be patient and we will get back to you as soon as we can.

[jagermesh]

Sorry, not sure what is wrong with Label step, but fix worth to review. It's significantly improve the speed in case when HTML contain SVG images.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 20.00000% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 63.10%. Comparing base (b751cbf) to head (b672638). Report is 12 commits behind head on master.

Files	Patch %	Lines
src/clone-node.ts	20.00%	2 Missing and 2 partials :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #462 +/- ## ========================================== + Coverage 62.93% 63.10% +0.17% ========================================== Files 10 10 Lines 580 580 Branches 143 143 ========================================== + Hits 365 366 +1 Misses 151 151 + Partials 64 63 -1 ```

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