Move apply_from_sdcard to fuse_sdcard_install

Move the sdcard installation function and all helper functions to a
separate file, and drop the dependency on common.h.

In the future, we want to move these functions into the install class.

Bug: 127071893
Test: unit tests pass
Change-Id: I0b7f7cbf0b68918e638e13878ca28bfca367088a