add matcher cache for proxy store and tsdb store API #433

Job	Run time
Go build with -tags=stringlabels	53s
Linters (Static Analysis) for Go	2m 54s
Check misspelled words	14s
Go build for different platforms	9m 30s
Thanos unit tests	11m 17s
Thanos end-to-end tests (8, 0)	4m 59s
Thanos end-to-end tests (8, 1)	4m 46s
Thanos end-to-end tests (8, 2)	3m 52s
Thanos end-to-end tests (8, 3)	4m 35s
Thanos end-to-end tests (8, 4)	7m 28s
Thanos end-to-end tests (8, 5)	4m 39s
Thanos end-to-end tests (8, 6)	4m 32s
Thanos end-to-end tests (8, 7)	4m 22s
	1h 4m 1s

Provide feedback