Don't open image links in new tab/window
I find it annoying that left-clicking on an image thumbnail opens a new tab. It's also inconsistent, since only image links have a `target="_blank"` attribute, none of the other types of links do.

I know this is a possibly major change in usability, but I think it's the right thing to do. You can still open links in a new tab with your middle mouse button after all (which is already required for other links already after all)

<details>
<summary>Patch</summary>

```patch
diff --git a/src/views/list.nim b/src/views/list.nim
index 4af3ad7..63009c3 100644
--- a/src/views/list.nim
+++ b/src/views/list.nim
@@ -15,7 +15,7 @@ proc renderList*(body: VNode; query: Query; list: List): VNode =
   buildHtml(tdiv(class="timeline-container")):
     if list.banner.len > 0:
       tdiv(class="timeline-banner"):
-        a(href=getPicUrl(list.banner), target="_blank"):
+        a(href=getPicUrl(list.banner)):
           genImg(list.banner)
 
     tdiv(class="timeline-header"):
diff --git a/src/views/profile.nim b/src/views/profile.nim
index 08404f1..3be58a6 100644
--- a/src/views/profile.nim
+++ b/src/views/profile.nim
@@ -18,7 +18,7 @@ proc renderProfileCard*(profile: Profile; prefs: Prefs): VNode =
       var size = "_400x400"
       if prefs.autoplayGifs and profile.userpic.endsWith("gif"):
         size = ""
-      a(class="profile-card-avatar", href=url, target="_blank"):
+      a(class="profile-card-avatar", href=url):
         genImg(profile.getUserpic(size))
 
       tdiv(class="profile-card-tabs-name"):
@@ -85,7 +85,7 @@ proc renderBanner(profile: Profile): VNode =
     if "#" in profile.banner:
       tdiv(class="profile-banner-color", style={backgroundColor: profile.banner})
     else:
-      a(href=getPicUrl(profile.banner), target="_blank"):
+      a(href=getPicUrl(profile.banner)):
         genImg(profile.banner)
 
 proc renderProtected(username: string): VNode =
diff --git a/src/views/tweet.nim b/src/views/tweet.nim
index a16fdd5..2c3f796 100644
--- a/src/views/tweet.nim
+++ b/src/views/tweet.nim
@@ -56,7 +56,7 @@ proc renderAlbum(tweet: Tweet): VNode =
               named = "name=" in photo
               orig = if named: photo else: photo & "?name=orig"
               small = if named: photo else: photo & "?name=small"
-            a(href=getPicUrl(orig), class="still-image", target="_blank"):
+            a(href=getPicUrl(orig), class="still-image"):
               genImg(small)
 
 proc isPlaybackEnabled(prefs: Prefs; video: Video): bool =
```

</details>