[SDK] Add exemplar reservoir to async metric storage #8490

Job	Run time
Bazel noexcept	18m 8s
Bazel asan config	12m 0s
Bazel nortti	23m 16s
Bazel on MacOS	29m 51s
Bazel	19m 56s
Bazel with async export	20m 23s
Bazel tsan config	20m 35s
Bazel valgrind	28m 37s
Bazel with external abseil	20m 32s
Benchmark	16m 36s
CMake test (with abseil)	8m 23s
CMake clang 14 (maintainer mode, async)	18m 10s
CMake clang 14 (maintainer mode, sync)	16m 57s
CMake do not install test (with otlp-exporter)	30m 0s
CMake gcc 4.8 (with otlp exporter)	14m 47s
CMake gcc 4.8 (without otlp exporter)	6m 13s
CMake gcc 12 (maintainer mode, async)	16m 15s
CMake gcc 12 (maintainer mode, C++11, async)	13m 30s
CMake gcc 12 (maintainer mode, sync)	10m 44s
CMake install test (with abseil)	6m 6s
CMake test (with modern protobuf,grpc and abseil)	28m 4s
CMake msvc (maintainer mode)	15m 14s
CMake test (with opentracing-shim)	6m 3s
CMake test (build shared libraries with otlp-exporter and static gRPC)	20m 47s
CMake test (with otlp-exporter)	20m 57s
CMake test (without otlp-exporter)	9m 41s
CMake C++20 test(Clang with libc++)	11m 25s
CMake C++20 test(GCC)	12m 39s
CMake test (without otlp-exporter and with async export)	7m 0s
Code coverage	15m 8s
Copyright	9s
DocFX check	1m 11s
Format	15s
markdown-lint	12s
misspell	8s
Plugin -> CMake	1m 25s
CMake -> exporter proto	17m 35s
Bazel Windows	35m 27s
Plugin -> CMake Windows	13m 12s
CMake (With async export) -> exporter proto	17m 29s
CMake -> exporter proto (Build as DLL)	22m 52s
	10h 7m 52s

Provide feedback