Windows 10 Emojis require two characters for navigation

Issue Type: Bug

What happened: I typed the 🏢 emoji using the Windows 10 emoji picker, and it changed it to �� in-editor when I closed the picker.

What did you expect to happen: I expected it to retain the 🏢 emoji.

How to reproduce it (as minimally and precisely as possible):

1. Install this extension
2. Create a new file
3. Press win+. to open the emoji picker
4. Insert the 🏢 emoji
5. Press ctrl, esc, or any key that closes the emoji picker (or press the close button on the emoji picker)

Disabling the vim extension prevented the issue. Copying and pasting the emoji from Notepad also prevents the issue.

Extension version: 0.12.0 VS Code version: Code 1.24.0 (6a6e02cef0f2122ee1469765b704faf5d0e0d859, 2018-06-06T17:35:40.560Z) OS version: Windows_NT x64 10.0.17133

System Info

Item	Value
CPUs	AMD Ryzen 5 1600X Six-Core Processor (12 x 3593)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: disabled_software rasterization: disabled_software video_decode: enabled video_encode: enabled vpx_decode: enabled webgl: enabled webgl2: enabled
Memory (System)	15.96GB (1.43GB free)
Process Argv	C:\Program Files\Microsoft VS Code\Code.exe [project path]
Screen Reader	no
VM	0%

[jpoon]

Workaround for the first issue, is to be in insert mode while using the emoji picker.

[liamdawson]

I found a separate issue in that the extension also treats 🏢 as two characters for navigation purposes (e.g. I have to press ll or 2l to move to the next character after the 🏢 character. Worth raising as a separate issue?