Print the thread name in the live TUI

To allow users to determine thread in a multithreaded application
corresponds to the "Thread X of Y" number displayed in the live view,
include the thread name that we collect in the TUI.

src/memray/reporters/tui.py

@@ -540,7 +540,7 @@ def __init__(self, pid: Optional[int], cmd_line: Optional[str], native: bool):
         self.pid = pid
         self.cmd_line = cmd_line
         self.native = native
-        self._seen_threads: Set[int] = set()
+        self._seen_threads: Dict[int, str] = {}
         self._max_memory_seen = 0
         super().__init__()
 
@@ -578,15 +578,15 @@ def watch_thread_idx(self, thread_idx: int) -> None:
         """Called when the thread_idx attribute changes."""
         self.query_one("#tid", Label).update(f"[b]TID[/]: {hex(self.current_thread)}")
         self.query_one("#thread", Label).update(
-            f"[b]Thread[/] {thread_idx + 1} of {len(self.threads)}"
+            f"[b]Thread[/] {thread_idx + 1} of {len(self.threads)} ({self.threads[thread_idx]})"
         )
         self.query_one(AllocationTable).current_thread = self.current_thread
 
     def watch_threads(self, threads: List[int]) -> None:
         """Called when the threads attribute changes."""
         self.query_one("#tid", Label).update(f"[b]TID[/]: {hex(self.current_thread)}")
         self.query_one("#thread", Label).update(
-            f"[b]Thread[/] {self.thread_idx + 1} of {len(threads)}"
+            f"[b]Thread[/] {self.thread_idx + 1} of {len(self.threads)} ({self.threads[self.thread_idx]})"
         )
 
     def watch_disconnected(self) -> None:
@@ -644,7 +644,11 @@ def display_snapshot(self) -> None:
         if self.paused:
             return
 
-        new_tids = {record.tid for record in snapshot.records} - self._seen_threads
+        new_tids = {
+            record.tid: record.thread_name
+            for record in snapshot.records
+            if record.tid not in self._seen_threads
+        }
         self._seen_threads.update(new_tids)
 
         if new_tids: