[BUILD] Accept path list in OPENTELEMETRY_EXTERNAL_COMPONENT_PATH #8866

Job	Run time
CMake clang 14 (maintainer mode, async)	13m 45s
CMake clang 14 (maintainer mode, sync)	13m 34s
CMake gcc 12 (maintainer mode, async)	7m 40s
CMake gcc 12 (maintainer mode, sync)	9m 31s
CMake test (without otlp-exporter)	7m 9s
CMake test (with abseil)	6m 13s
CMake clang 14 (maintainer mode, abiv2)	14m 31s
CMake msvc (maintainer mode)	7m 30s
CMake test (with opentracing-shim)	5m 37s
CMake C++14 test(GCC)	4m 40s
CMake test (without otlp-exporter and with async export)	4m 49s
CMake do not install test (with otlp-exporter)	14m 40s
CMake test (with modern protobuf,grpc and abseil)	20m 5s
CMake test (with otlp-exporter)	13m 53s
CMake C++17 test(GCC)	5m 48s
CMake C++20 test(GCC)	8m 42s
CMake C++20 test(Clang with libc++)	11m 53s
Bazel	14m 52s
Bazel with async export	12m 6s
Bazel valgrind	14m 9s
Bazel with external abseil	14m 22s
CMake install test (with abseil)	4m 31s
CMake test (build shared libraries with otlp-exporter and static gRPC)	13m 38s
Plugin -> CMake	2m 4s
Bazel asan config	17m 0s
Bazel noexcept	13m 53s
Bazel nortti	14m 14s
Bazel on MacOS	29m 42s
Benchmark	8m 5s
Bazel tsan config	14m 45s
Copyright	7s
Format	15s
Code coverage	17m 46s
DocFX check	1m 17s
markdown-lint	7s
misspell	3s
CMake -> exporter proto	13m 15s
Bazel Windows	23m 30s
Plugin -> CMake Windows	8m 45s
CMake (With async export) -> exporter proto	12m 50s
CMake -> exporter proto (Build as DLL)	14m 16s
	7h 15m 32s

Provide feedback