feat: show EML CC and BCC in mail detail page

[Jnoack331]

This adds extra information to the detail page and would help if sending via the files somehow failes.

[shyim]

When you need it only on the detail page, we should extract it from EML. or what do you think @tinect

[Jnoack331]

@shyim @tinect The idea was also to have a database backup of the CC/BCC when somehow the EML files have wrong permissions or some other files problem.

[tinect]

I agree with @shyim.
With the introduction of the EML-File, we plan to remove database entries reflecting the email content to save storage and mysql-traffic.

Brief overview of the plan: HTML will be stripped and TO and subject might stay. for searchability. Detailed information will then be loaded from the eml file if requested on the detail page.

Emails are stored securely in the private filesystem. Filesystem access issues are outside the scope of plugins and should be addressed separately.

Thank you anyway, @Jnoack331 🤗

[tinect]

Hey @Jnoack331 would you like to start implementing loading the CC and BCC from the file?

[Jnoack331]

@tinect sure, i can take a look 👍

[Jnoack331]

@tinect @shyim i added the changes to read the CC and BCC from the eml file. Is this OK or do you want any changes?

[Jnoack331]

Is it fine like this, or do you need any changes?