fix(mask): add support for -webkit-mask and -webkit-mask-image

[amiratak88]

Description

Add support for mask and mask-image properties for browsers that support them via webkit.

Motivation and Context

Types of changes

• [x] 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)
• [ ] 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.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[vivcat[bot]]

👋 @amiratak88

💖 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.

[codecov[bot]]

Codecov Report

Patch coverage: 75.00% and no project coverage change

Comparison is base (b751cbf) 62.93% compared to head (569a944) 62.93%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #382 +/- ## ======================================= Coverage 62.93% 62.93% ======================================= Files 10 10 Lines 580 580 Branches 143 143 ======================================= Hits 365 365 Misses 151 151 Partials 64 64 ``` | [Impacted Files](https://codecov.io/gh/bubkoo/html-to-image/pull/382?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=%E5%B4%96) | Coverage Δ | | |---|---|---| | [src/embed-images.ts](https://codecov.io/gh/bubkoo/html-to-image/pull/382?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=%E5%B4%96#diff-c3JjL2VtYmVkLWltYWdlcy50cw==) | `78.04% <75.00%> (ø)` | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=%E5%B4%96). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=%E5%B4%96)

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[lorenzhh]

What is the status of this PR?

[gilkeyio]

Would love to see this get merged! I've run a local fork with these changes, and they work great for me.