SEO Tools: add suggested character count for title and description fields

### Impacted plugin

Jetpack

### What

It would be nice if the editor fields could clearly suggest how many characters should be used in both fields

### How

The SEO fields use the `CountedTextArea` component, defined here:
https://github.com/Automattic/jetpack/blob/e4806c41d04d318b4a2915efdb3eb16bd76c38c7/projects/plugins/jetpack/extensions/blocks/seo/counted-textarea.js#L5

That component includes different text when you go over a suggested limit. We use that property for the title field:

https://github.com/Automattic/jetpack/assets/426388/7382627f-fb15-4ab3-a39c-ab13d70ada43

However:

- [x] We do not use that property for the description field. #30890
- [ ] It would be nice if the suggested count was displayed from the start maybe.

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Internal reference:
p1684874539201249-slack-C0299DMPG

Start with projects/plugins/jetpack/extensions/blocks/seo/counted-textarea.js and inspect how the suggested-limit text is currently shown. Trace its use in the SEO title and description fields, then verify that the suggested character counts are visible before either field exceeds its limit.

Written by the indexing model from the issue text.