cmake: copy resources in build folder.

[iMineLink]

Description of Changes

copy resources from bin to pcsx2 target build folder when building with cmake.

Rationale behind Changes

make it easier to run the pcsx2 target via vscode cmake integration on windows.

Suggested Testing Steps

check that building and running an all platforms is not broken.
on windows, check that you can run the pcsx2 target via vscode cmake integration and it finds the resources folder.

[TellowKrinkle]

add_custom_command lets you specify multiple commands to run in series
If you do the two commands separately, on multicore builds, they could run out of order AFAIK

[iMineLink]

thanks for the tip, now a single add_custom_command call specifies both directories creation and file copy commands.