Enhancement: Add ability to filter meta tags

### Impacted plugin

Social

### What

It will be great to add ability to filter meta tags especially image

### How

Add `apply_filters` function to allow plugin developers to substitute their own image.

https://github.com/Automattic/jetpack/blob/trunk/projects/plugins/social/src/class-meta-tags.php#L278

Start in projects/plugins/social/src/class-meta-tags.php around line 278 and inspect how the image meta tag is assembled. Add a documented filter point so plugin developers can substitute the image, then verify that the generated image meta tag uses the filtered value.

Written by the indexing model from the issue text.