[feature] Support setting private notes on accounts (#1982)

* Support setting private notes on accounts

* Reformat comment whitespace

* Add missing license headers

* Use apiutil.ParseID

* Rename Note model and cache to AccountNote

* Update golden cache config in test/envparsing.sh

* Rename gtsmodel/note.go to gtsmodel/accountnote.go

* Update AccountNote uniqueness constraint name

Now has same prefix as other indexes on this table.

---------

Co-authored-by: tobi <31960611+tsmethurst@users.noreply.github.com>

internal/db/bundb/relationship.go

@@ -85,6 +85,19 @@ func (r *relationshipDB) GetRelationship(ctx context.Context, requestingAccount
 		return nil, fmt.Errorf("GetRelationship: error checking blockedBy: %w", err)
 	}
 
+	// retrieve a note by the requesting account on the target account, if there is one
+	note, err := r.GetNote(
+		gtscontext.SetBarebones(ctx),
+		requestingAccount,
+		targetAccount,
+	)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		return nil, fmt.Errorf("GetRelationship: error fetching note: %w", err)
+	}
+	if note != nil {
+		rel.Note = note.Comment
+	}
+
 	return &rel, nil
 }