[Hristo313]

Closes #722

Update the Single Selection Combo xplat topics

Also updated the samples:
Angular -> IgniteUI/igniteui-angular-samples#4072
React -> IgniteUI/igniteui-react-examples#1139
WC -> IgniteUI/igniteui-wc-examples#1310
Blazor -> IgniteUI/igniteui-blazor-examples#1356

Checklist:

• check topic's TOC/menu and paragraph headings
• Include TOC topic labels in the topic content when it has a valuable update, is new, or is considered preview / beta
• link to other topics using ./page.mdx or ../relative/path.mdx (.mdx extension required)
• at the References section at the end of the topic add links to topics, samples, etc
• reference API documentation instead of adding a section with API

• use valid component names - [Data] Grid, IgxSelectComponent, <igx-combo>
• use spell checker tool (VS Code, Grammarly, Microsoft Editor)
• add inline code blocks for the names of classes / tags / properties
• add language descriptor for the code blocks
• check if links function by running the check-api/mdx npm commands
• check if sample is working and fully visible in the topic
• check if sample is working and fully visible in the StackBlitz
• check if code blocks match the code in StackBlitz demo
• add or update meaningful llms.description metadata and run npm run check:llms-metadata

• follow SEO guidelines to fill topic's metadata (SEO guidelines)

• do not resolve requested changes (leave that to the reviewer)

[DiLazarova]

Review for Combo / React / Chrome
It appears that there are images with the background and icons embedded within the Do/Don/t section's frame.

[DiLazarova]

Single Combo - Review - React/ Chrome

1. Only “Material Combo” has two types: “Box” and “Border.” The other themes support only one option.

There is one additional example in the Figma File: Figma Design

This should be changed in every other section

[DiLazarova]

The following sample shows a header and an item in each size. Since the frame is read-only items shouldn't be selectable.

[DiLazarova]

Dropdown item section

The Dropdown items in Indigo looks weird:

UI Kit:

Also Fluent - there is now shadow like the example.

UI Kit:

The same problem appears in Dropdown Items Section!