Extract text from HTML part for message preview

Checklist

• I have used the search function to see if someone else has already submitted the same feature request.
• I will describe the problem with as much detail as possible.
• This issue only contains a request for one single feature, not multiple (related) features.

App version

5.911-SNAPSHOT

Problem you are trying to solve

Sometimes the message preview text doesn't match the text that is displayed when the message is opened for viewing. This is because for messages that provide both a text/plain and text/html part we extract the preview from the text/plain part, but display the text/html part. Sometimes these parts contain different text (mostly because the applications that produce the message mess up converting HTML to plain text, i.e. by including things like the contents of <style> elements).

Suggested solution

Extract preview text from the same part that we use when displaying the message.

Screenshots / Drawings / Technical details

No response

No files, tests, or entry points are named. Locate the message preview extraction and message display paths, then compare which MIME part each uses; the work is done when the preview is extracted from the same part used for viewing and matches the displayed message text.