Support memory-related features introduced in VS Code

[thegecko]

Feature Description:

In the January 2022 release, VS Code introduced support for memory related features, specifically viewing and editing binary data for variables.

During debug, if the adapter supports readMemoryRequest, writeMemoryRequest and a variable contains the memoryReference property, then an inline button appears to allow viewing the memory.

In VS Code this directs the user to install and use the hex editor extension.

As we have similar functionality in the form of memory inspection, I propose Theia mimics this functionality, but allows the developer to choose which memory viewer extension to contribute for the UI