Update Imports On File Move: does not persist file extension

[miguelsolorio]

Issue Type: Bug

Testing #50488

Example

Resulting error

When moving a js file while using the "Update Imports On File Move" setting and the import has the file extension explicitly set, the auto update will strip out the ".js" extension. This causes issues with the js file referencing it as it needs the extension name.

VS Code version: Code - Insiders 1.24.0-insider (bfd155e, 2018-05-29T06:13:09.810Z)
OS version: Darwin x64 17.5.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz (8 x 2200)
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: enabled rasterization: enabled video_decode: enabled video_encode: enabled vpx_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	4, 5, 5
Memory (System)	16.00GB (0.78GB free)
Process Argv	/Applications/Visual Studio Code - Insiders.app/Contents/MacOS/Electron -psn_0_5203190
Screen Reader	no
VM	20%

[mjbvz]

This issue was moved to microsoft/TypeScript#24493