fix issue 1255: Move snippets to the snippets location #2

[yishengjin1413]

Related to #10774 .

1. Please help to check this PR first . Some codesnippets are changed in dotnet/docs repo and the PR is used to move the changes to samples repo. Before that pr merged, this pr build may get some warnings or the page may looks different from before.
2. There are four topics left which I didn't fix. Since I can't find the codesnippet from samples repo. So please manually fix them.
   1. docs\csharp\programming-guide\strings\index.md
   2. docs\csharp\programming-guide\arrays\single-dimensional-arrays.md
   3. docs\visual-basic\reference\command-line-compiler\imports.md
   4. docs\visual-basic\programming-guide\language-features\events\index.md
3. For deleting the the snippets in this repo, I think you can remove all the snippet folders after this four topics fixed. Or I can send a separate PR to delete no-used snippets later after these two PR merged.

Contributes #1255

[BillWagner]

closing and reopening to start a new build to pick up new samples PRs

[mairaw]

Thanks @yishengjin1413! I've checked a few before and after and they all look great. I'll check the topics you listed and create a PR to remove all codesnippet folders.

Thank you so much for your help with this! ❤️