WCOW tests can be integrated directly into existing LCOW tests as
subtests, after generalizing the original (LCOW-only) tests to run both
types of uVMs and containers.

Break the change into two:
(1) move (and rename) the original LCOW-only tests; and
(2) generalize the tests and add the WCOW components.

To simplify the diffs, this commit only includes the first process.
Specifically, move:
 - `lcow_bench_test.go` to `uvm_bench_test.go`
 - `lcow_container_test.go` to `container_test.go`
 - `lcow_test.go` to `lcow_uvm_test.go`

Within `lcow_uvm_test.go`, combine and generalize kernel arg tests
(i.e., `TestLCOW_UVMNoSCSINoVPMemInitrd` and
`TestLCOW_UVMNoSCSISingleVPMemVHD`) to `TestLCOW_UVM_KernelArgs`.

Combine and generalize boot/time tests (e.g.,
`TestLCOW_TimeUVMStartVHD`, `TestLCOW_UVMStart_KernelDirect_VHD`) to
`TestLCOW_UVM_Boot`.

Also, since go1.21, `"github.com/Microsoft/hcsshim/internal/sync"` is no
longer necessary, so replace it with `"sync".OnceValue[s]`.

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

Expose `FileBindingSupported()` function from `"internal\jobcontainers"`
so it can be used in functional testing code.

Switch from `sync.Once` to checking for `bindfltapi.dll` during package
init, since the check is (relatively) cheap.

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

Un-skip and fix WCOW uVM and container tests.
Add WCOW:
- uVM benchmarks
- vSMB tests
- Host Process tests

For WCOW host process tests, add dedicated tests for setting
username, and verifying hostname and volume mounts.

Fix bug where removing a direct-mapped vSMB share fails.

Run (non-virtualization/uVM) functional tests within CI.

Starting Host Process containers requires SYSTEM to create a
process with a specified token, so use PsExec.exe (from sysutils)
to run tests.

Make sure container specs are created with the default working
directory (`C:\`), similar to how `internal\cmd` works).

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>