Add file memory provider #2997

Job	Run time
Build docs	35s
Coding style	1m 5s
Spellcheck / Run spell check	13s
Fast builds / Fast builds (windows-latest, OFF, ON, OFF)	1s
Fast builds / Fast builds (windows-latest, OFF, OFF, OFF)	1s
Fast builds / Fast builds (ubuntu-latest, ON, ON, -DCMAKE_BUILD_TYPE=Release -DUMF_BUILD_BENCHMARKS=ON -DUMF_BU...	2m 10s
Fast builds / Fast builds (ubuntu-latest, OFF, OFF, -DCMAKE_BUILD_TYPE=Release -DUMF_BUILD_BENCHMARKS=ON, OFF)	1m 25s
Fast builds / Fast builds (ubuntu-latest, OFF, ON, -DCMAKE_BUILD_TYPE=Release, ON)	2m 29s
Fast builds / Fast builds (ubuntu-20.04, OFF, ON, -DCMAKE_BUILD_TYPE=Release, ON)	1s
Qemu	0s
Sanitizers	0s
Basic builds	0s
ProxyLib	0s
GPU	0s
Benchmarks	0s
MultiNuma	0s
Valgrind	0s
	8m 0s

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