Improve support for multiline notes

[mnd]

Is your feature request related to a problem? Please describe. When I writing new Note with embedded newlines they displayed on web interface as single line message. This happens because newlines stored in DB and returned to HTML code as is without replacement to </br> tag

Describe the solution you'd like Describe alternatives you've considered I'm not expert in current fediverse infrastructure and can't decide which solution would be better:

1. Replace newlines with </br> when post created and stored to DB. In this case all recipients will got message with HTML markup.
2. Replace newlines with </br> when post displayed on WEB interface. In this case recipients will got message as it was written, but all newlines will be displayed correctly on the web.

[mnd]

Displaying was fixed by #1090

Using <br /> while saving local post was not provided yet