[lldb][debugger][NFC] Add broadcast bit for category-based progress events. (llvm#81169)

This commit adds a new broadcast bit to the debugger. When in use, it
will be listened to for progress events that will be delivered and kept
track of by category as opposed to the current behaviour of coming in
one by one.

Author: chelcassanova

lldb/include/lldb/API/SBDebugger.h

@@ -46,6 +46,7 @@ class LLDB_API SBDebugger {
       eBroadcastBitProgress = (1 << 0),
       eBroadcastBitWarning = (1 << 1),
       eBroadcastBitError = (1 << 2),
+      eBroadcastBitProgressCategory = (1 << 3),
   };
 
   SBDebugger();

lldb/include/lldb/Core/Debugger.h

@@ -84,6 +84,7 @@ class Debugger : public std::enable_shared_from_this<Debugger>,
     eBroadcastBitWarning = (1 << 1),
     eBroadcastBitError = (1 << 2),
     eBroadcastSymbolChange = (1 << 3),
+    eBroadcastBitProgressCategory = (1 << 4),
   };
 
   using DebuggerList = std::vector<lldb::DebuggerSP>;