timeline: auto-add yourself to your home timeline

This is the most intuitive, and damus iOS does the same thing. You
have to follow yourself, sorry. Otherwise you won't see your posts
when you post which is confusing.

Fixes: https://github.com/damus-io/notedeck/issues/509

crates/notedeck/src/filter.rs

@@ -192,13 +192,14 @@ impl FilteredTags {
 
 /// Create a filter from tags. This can be used to create a filter
 /// from a contact list
-pub fn filter_from_tags(note: &Note) -> Result<FilteredTags> {
+pub fn filter_from_tags(note: &Note, add_pubkey: Option<&[u8; 32]>) -> Result<FilteredTags> {
     let mut author_filter = Filter::new();
     let mut hashtag_filter = Filter::new();
     let mut author_res: Option<FilterBuilder> = None;
     let mut hashtag_res: Option<FilterBuilder> = None;
     let mut author_count = 0i32;
     let mut hashtag_count = 0i32;
+    let mut has_added_pubkey = false;
 
     let tags = note.tags();
 
@@ -223,6 +224,13 @@ pub fn filter_from_tags(note: &Note) -> Result<FilteredTags> {
                 continue;
             };
 
+            if let Some(pk) = add_pubkey {
+                if author == pk {
+                    // we don't need to add it afterwards
+                    has_added_pubkey = true;
+                }
+            }
+
             author_filter.add_id_element(author)?;
             author_count += 1;
         } else if t == "t" {
@@ -237,6 +245,14 @@ pub fn filter_from_tags(note: &Note) -> Result<FilteredTags> {
         }
     }
 
+    // some additional ad-hoc logic for adding a pubkey
+    if let Some(pk) = add_pubkey {
+        if !has_added_pubkey {
+            author_filter.add_id_element(pk)?;
+            author_count += 1;
+        }
+    }
+
     author_filter.end_field();
     hashtag_filter.end_field();