feat(ol-style-text): added fill and stroke props

Thank you for the awesome library, it has saved me a ton of work. I've been trying to style some labels over map markers, and realized that I was unable to set the color of the text nor the stroke.

Description

Upon further digging, I came across this PR so I followed the same template used there and just added the missing props.

Motivation and Context

These two props are important to style text, and OlStyleText already implements those.

How Has This Been Tested?

I tested this by pointing my project's npm to my local copy and tested the color and stroke modifications according to usage.

Screenshots (if appropriate):

Types of Changes

[ ] Bug fix (non-breaking change that fixes an issue)
[x] New feature (non-breaking change that adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[x] Documentation Update
[ ] Other (Tooling, Dependency Updates, etc.)

Checklist:

[x] My code follows the code style of this project.
[x] My change requires a change to the documentation.
[x] I have updated the documentation accordingly.

If you added a new component feature (layer, geom, source, etc.), please be sure to update the documentation:

[ ] Add component to output.globals in vite.config.ts
[ ] Create a src/demos/<Component>Demo.vue
[ ] Create a docs/componentsguide/<Category>/<Feature>/index.md containing the Demo and documentation for the component
[ ] Add the docs page to docs/.vitepress/config.ts

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MelihAltintas / vue3-openlayers