Improve HTML entity handling in meta tag generation

[KuJoe]

Enhanced the escaping and decoding of HTML entities for meta tag content in head_contents() and generate_meta() functions. This ensures that apostrophes and similar entities are consistently converted to single quotes, improving the accuracy and readability of generated meta tags.

This prevents website previews/embeds from showing things like don't and can't instead of don't and can't.

[danpros]

Hi,

Is this tested again some funny string for description/title eg. < > or quote etc.? sometimes users add This is "me" as blog title/description etc. or this is 'cool' just in case some html code added to the title / description.