ASV: add benchmark for reindex with MultiIndex containing dates
- [x] closes #23735
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).

Adding a benchmark per the discussion in the linked issue. 

```
from asv_bench.benchmarks.reindex import Reindex

b = Reindex()
b.setup()

%timeit b.time_reindex_multiindex_no_cache_dates()
```

```
603 ms ± 20.5 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)    <- 1.4.2
45.6 ms ± 995 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)  <- main
```
thanks @lukemanley very nice!