[lldb-vscode] Add Support for Module Event

Summary:
Whenever a module is created, removed or changed, lldb-vscode is now sending an event that can be interpreted by the IDE so that modules can be rendered in the IDE, like the tree view in this screenshot

{F12229758}

Reviewers: wallace, clayborg, kusmour, aadsm

Reviewed By: clayborg

Subscribers: cfe-commits, labath, lldb-commits

Tags: #lldb, #clang

Differential Revision: https://reviews.llvm.org/D82477