Storage Provider pallet benchmarks

[Jinxit]

The storage provider pallet needs benchmarks in order to calculate the real weights. An initial implementation exists in #740, but there are still multiple externalities left to test.

• register_storage_provider feat(storage-provider): benchmark register & pre_commit #740
• pre_commit_sectors feat(storage-provider): benchmark register & pre_commit #740
• prove_commit_sectors
• submit_windowed_post
• declare_faults
• declare_faults_recovered
• terminate sectors

In addition to this, we will also need to run the benchmark with the production configuration, see #783.