Show full error snippets in LSP errors

[ArmorDarks]

Given the type

// @flow

export type Term = { prop: string }

compare LSP error with original Flow error:

Because LSP error doesn't show full code snippet in error, it is extremely hard to understand at a glance what to referencing 1 and 2

Flow 0.91.0, tested with flow-for-vscode 1.0.1, default settings.