Update to link to forum posts and message owners

[cholmcc]

• This patch adds interface the the project pages to help find forum posts (in the module-discussion and module-support forums) related to the project.
• It also adds interface to post a new topic to those sub-forums. The message is auto-filled with the sub-forum, title of the project, in square brackets [], and a link to the project page.
• Adds a button to send a direct message to all project owners. As with posts, the message draft has some information already filled in.

To achieve this, some concrete chances that are made

• Add some icons to the Header.svelte template. These are icons for direct messages, new posts, and search of forums.
• The ProjectSection.svelte template is updated to show the above interfaces in the project information section of the project page (where the owners are also listed).

See also screenshot below.

To continue the proposal done in How to give feedback on modules/projects and reach the developer

Yours,
Christian

[cholmcc]

The PR has been updated with

• Titles of sub-forums changed to Module Discussion and Module Support
• The sub-forum titles are prefixed with a square that has the colour of the sub-forum.
• The Message button now says Message all if more than one owner is defined.

See also screenshots below

Yours,
Christian