[lldb-dap] Add command line option `--connection-timeout` (#156803)

# Usage

This is an optional new command line option to use with `--connection`.

```
--connection-timeout <timeout>    When using --connection, the number of seconds to
        wait for new connections after the server has started and after all clients
        have disconnected. Each new connection will reset the timeout. When the
        timeout is reached, the server will be closed and the process will exit.
        Not specifying this argument or specifying non-positive values will cause
        the server to wait for new connections indefinitely.
```

A corresponding extension setting `Connection Timeout` is added to the
`lldb-dap` VS Code extension.

# Benefits

Automatic release of resources when lldb-dap is no longer being used
(e.g. release memory used by module cache).

# Test

See PR.

1 files changed, 5 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
index 66aa070..51debcf 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
@@ -1533,6 +1533,7 @@ class DebugAdapterServer(DebugCommunication):
         env: Optional[dict[str, str]] = None,
         log_file: Optional[TextIO] = None,
         connection: Optional[str] = None,
+        connection_timeout: Optional[int] = None,
         additional_args: list[str] = [],
     ) -> tuple[subprocess.Popen, Optional[str]]:
         adapter_env = os.environ.copy()
@@ -1550,6 +1551,10 @@ class DebugAdapterServer(DebugCommunication):
             args.append("--connection")
             args.append(connection)
 
+        if connection_timeout is not None:
+            args.append("--connection-timeout")
+            args.append(str(connection_timeout))
+
         process = subprocess.Popen(
             args,
             stdin=subprocess.PIPE,