Write full types and fix related bugs

Also fixes #4.

src/site/pug/post.pug

@@ -5,16 +5,22 @@ html
 	head
 		meta(charset="utf-8")
 		meta(name="viewport" content="width=device-width, initial-scale=1")
-		title= `${post.getIntroduction()} | Bibliogram`
+		title
+			if post.getCaptionIntroduction()
+				=post.getCaptionIntroduction()
+			else
+				=`Post from @${post.getBasicOwner().username}`
+			=` | Bibliogram`
 		link(rel="stylesheet" type="text/css" href="/static/css/main.css")
 		script(src="/static/js/pagination.js" type="module")
 	body.post-page
 		main.post-page-divider
 			section.description-section
 				header.user-header
-					img(src=post.proxyOwnerProfilePicture width=150 height=150 alt="").pfp
-					a.name(href=`/u/${post.extendedOwner.username}`)= `${post.extendedOwner.full_name} (@${post.extendedOwner.username})`
-				p.description= post.getCaption()
+					img(src=post.ownerPfpCacheP width=150 height=150 alt="").pfp
+					a.name(href=`/u/${post.getBasicOwner().username}`)= `${post.data.owner.full_name} (@${post.getBasicOwner().username})`
+				if post.getCaption()
+					p.description= post.getCaption()
 			section.images-gallery
-				for image in post.getChildren()
-					img(src=image.proxyDisplayURL alt=image.getAlt() width=image.data.dimensions.width height=image.data.dimensions.height).sized-image
+				for image in post.children
+					img(src=image.getDisplayUrlP() alt=image.getAlt() width=image.data.dimensions.width height=image.data.dimensions.height).sized-image