Support lockfile-explorer for subspace feature

[L-Qun]

Summary

Currently, if a repo is enabled with subspace feature, the lockfile-explorer command is no longer working. It complains that Error: [Error: File does not exist

This is due to that in subspace, we moved the common/temp folder as well as the pnpm-workspace.yaml file location.

This PR is to address this issue. Users now will be able to input the subspace name when calling the lockfile-explorer command, like lockfile-explorer --subspace <subspace_name>. The command will use the default subspace if it is not provided.

How it was tested

Manually tested with Rushstack repo locally.