feat: optimize the code block copy

[pengzhanbo]

Before submitting the PR, please make sure you do the following

• [x] Read the Contributing Guidelines.
• [x] Provide a description in this PR that addresses what the PR is solving. If this PR is going to solve an existing issue, please reference the issue (e.g. close #123).

What is the purpose of this pull request?

• [ ] Bug fix
• [x] New feature
• [ ] Other

Description

• Generate HTML text for the copy button in the plugin-prismjs/ plugin-shiki, and insert it into the code block.
• plugin-copy-code only provides functionality for the copy button and default styles.

[coveralls]

Pull Request Test Coverage Report for Build 9185613900

Details

• 24 of 25 (96.0%) changed or added relevant lines in 4 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+1.5%) to 58.351%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
plugins/plugin-prismjs/src/node/prismjsPlugin.ts	0	1	0.0%
<!--	Total:	24	25	96.0%	-->

Files with Coverage Reduction	New Missed Lines	%
plugins/plugin-prismjs/src/node/prismjsPlugin.ts	1	4.35%
<!--	Total:	1		-->

Totals
Change from base Build 9161313702:	1.5%
Covered Lines:	1048
Relevant Lines:	1617

---

💛 - Coveralls

[Mister-Hope]

Also, I did not find any thing about vp-copy-ignore class in current codes, so what's this option for?

When users are using twosplash, can we still provide the correct content?

[Mister-Hope]

BTW, I still dislike this PR change, as it splits a whole copy-code functionality inside 2 plugins, and users do not benefit from it in most cases.

The only thing it improves is removing a delay option, but the docs will confuse both the developers and the users. The ideal situation is that every theme should have a highlighter built-in, and if it does not bundle the copy code plugin, then users might get greatly confused when reading the copy code plugin docs.

We don't need any SSG render or SEO with the copy button actually, we just need a client side a11y support.

The things I actually concern is that can the 2 highlighter plugin provide a client side transformer, guiding the copy code plugin to make some transform to get the correct code.

[pengzhanbo]

Also, I did not find any thing about vp-copy-ignore class in current codes, so what's this option for?

When users are using twosplash, can we still provide the correct content?

For example, using twoslash will inject additional content into the code block, and you can also add a class name vp-copy-ignore to this additional content to prevent it from being copied. You can think of vp-copy-ignore as a preset. I have considered making ignore an optional configuration.