[EXPORTER] Prometheus: Sanitize labels according to spec #8533

Job	Run time
Bazel noexcept	18m 24s
Bazel asan config	11m 21s
Bazel nortti	19m 40s
Bazel on MacOS	27m 20s
Bazel	18m 56s
Bazel with async export	20m 44s
Bazel tsan config	20m 33s
Bazel valgrind	21m 56s
Bazel with external abseil	20m 6s
Benchmark	12m 45s
CMake test (with abseil)	7m 54s
CMake clang 14 (maintainer mode, async)	21m 3s
CMake clang 14 (maintainer mode, sync)	17m 26s
CMake do not install test (with otlp-exporter)	21m 4s
CMake gcc 4.8 (with otlp exporter)	21m 55s
CMake gcc 4.8 (without otlp exporter)	6m 53s
CMake gcc 12 (maintainer mode, async)	17m 7s
CMake gcc 12 (maintainer mode, C++11, async)	13m 29s
CMake gcc 12 (maintainer mode, sync)	12m 49s
CMake install test (with abseil)	9m 24s
CMake test (with modern protobuf,grpc and abseil)	27m 24s
CMake msvc (maintainer mode)	13m 11s
CMake test (with opentracing-shim)	6m 0s
CMake test (build shared libraries with otlp-exporter and static gRPC)	19m 57s
CMake test (with otlp-exporter)	20m 33s
CMake test (without otlp-exporter)	6m 34s
CMake C++20 test(Clang with libc++)	17m 5s
CMake C++20 test(GCC)	14m 46s
CMake test (without otlp-exporter and with async export)	7m 25s
Code coverage	13m 28s
Copyright	7s
DocFX check	1m 18s
Format	16s
markdown-lint	8s
misspell	5s
Plugin -> CMake	1m 8s
CMake -> exporter proto	20m 43s
Bazel Windows	38m 50s
Plugin -> CMake Windows	8m 47s
CMake (With async export) -> exporter proto	17m 24s
CMake -> exporter proto (Build as DLL)	17m 50s
	9h 53m 48s

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