Finish implementation of plugin context

[mmorhun]

Plugin context is passed to start function on plugin activation. Is is already implemented partially, but still misses some pieces.
For now in context project we have:

• extensionPath
• subscriptions
• asAbsolutePath

and miss:

• logPath Implement logPath for plugin context. #3660
• globalState [plugin-in] Implement Plugin Context 'globalState' and 'workspaceState' #3732
• storagePath [plug-in] Implement Plugin Context 'storagePath' #3733
• workspaceState [plugin-in] Implement Plugin Context 'globalState' and 'workspaceState' #3732

For more details see VSCode docs.

[mmorhun]

All issues from the list are completed.