benchmarks: add string compression benchmark #6604

Job	Run time
Rust/C++ FFI tests (tsan)	1m 54s
C++ API (coverage)	1m 4s
Rust/C++ FFI tests (asan)	2m 6s
Rust tests (asan)	7m 0s
Rust tests (tsan)	6m 32s
Rust tests (miri)	1m 35s
Mirror DuckDB to R2 / Resolve DuckDB version and check R2	7s
Mirror DuckDB to R2 / Mirror DuckDB ${{ matrix.archive }} to R2	0s
DuckDB libraries available in R2	3s
Rust tests (coverage) (tests)	6m 38s
	26m 59s

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