Markdown editor improvements

[fgatti675]

As per user feedback:

• When an image is uploaded to the Markdown editor, it should include a crop menu for better control over the image display.
• If I reuse the same image by copy-pasting it into the editor, it gets uploaded multiple times to the database, which leads to unnecessary duplicates. Ideally, there should be image reusability without re-uploading.
• There should be an option to add alt text to images, which is important both for accessibility and SEO.
• The Markdown editor should fully support Markdown tables and render them properly.
• When inserting URLs into text, the "trash/delete" icon doesn't always work properly, and sometimes the only way to remove the link is to delete the whole word and retype it.
• Since we use FireCMS extensively for articles, blog posts, news content, etc., and often in multiple languages, we’ve noticed that handling images and copy-pasting behavior can be quite frustrating and time-consuming.