Fix text direction in form

[MizukiTemma]

Short description

This PR fixes text direction of the title and content field.

Proposed changes

• Pass right_to_left in the event, POI and imprint view too, which is already used in the page form to set the text direction of TinyMCE.
• Add text_direction in the event, POI, imprint and page view to set the text direction of title input field in the template.

Side effects

• right_to_left and text_direction have almost the same function but I let both exist, because right_to_left is already being used in several places and it does not look cool (in my opinion) to write text_direction == "rtl" or something repeatedly 😅
• If I remember correctly, there was once a discusion about fixing the text direction of title field but it was rejected/postponed due to some technical problem or complexity or something. Though I couldn't find such thema in the repository, it may be a wrong memory. If you remember or know such (potential) problem, please comment 👀

Resolved issues

Fixes: #3290

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