Errors shown one at a time only in a source file and types not shown on hover if there is an error in the same file

1) reason-vscode plugin shows only one error at a time and
2) does not show type when there is an error elsewhere in the same file.
I thought these might be related problems and filed in one issue.

For example:

Example 1. There are errors with both variables `first_error` and `second_error`, but it's showing the error for the first one only.

Example 2. There is a type error with `first_error` and a syntax error with `second_error`, but the plugin is showing on the syntax error and the type error will slip away until the syntax error is fixed.

Example 3. (no type when there is an error) In the screenshot below my cursor was on the `some_int`, but it's type was not shown, as there is an error below (screenshot removes my cursor though, but it is on `some_int` with no type shown.)

Both of these problems are somehow absent in `Ocaml and Reason IDE` by Darrin Morrison, if that's of any help.

Start by reproducing the three reported cases in the reason-vscode plugin and compare them with the behavior shown for Ocaml and Reason IDE. Trace how multiple diagnostics and hover type information are produced; done means both errors remain visible and the type still appears when another error exists in the file.

Written by the indexing model from the issue text.