Import MKL via //third-party/mkl targets (#126371)

Summary:

This is a step towards upgrading the MKL library and using a buckified targets rather than importing from TP2.

- Add new `//third-party/mkl:mkl_xxx` targets that are currently aliases to `third-party//IntelComposerXE:mkl_xxx`.
- Switch usage of `external_deps = [("IntelComposerXE", None, "mkl_xxx")]` to `deps = ["fbsource//third-party/mkl:mkl_xxx"]`

Note that this only changes references to `mkl_xxx` references in `IntelComposerXE` but not references to "svml" or "ipp*".

Test Plan: sandcastle

Differential Revision: D57360438

defs.bzl

@@ -1,7 +1,7 @@
 def get_blas_gomp_arch_deps():
     return [
         ("x86_64", [
-            "third-party//IntelComposerXE:{}".format(native.read_config("fbcode", "mkl_lp64", "mkl_lp64_omp")),
+            "fbsource//third-party/mkl:{}".format(native.read_config("fbcode", "mkl_lp64", "mkl_lp64_omp")),
         ]),
         ("aarch64", [
             "third-party//OpenBLAS:OpenBLAS",