BENCH: fix noisy asv benchmarks that were running on exhausted generators
Generators get consumed on first use, yielding abnormally fast benchmark times on the `n>1` iterations. Fortunately we can instruct `asv` to call `setup()` prior to every sample by setting `number = 1` and `repeat` appropriately. My local runs suggest the typical number of samples is `~150-250`, so an upper limit of `250` appears to be a good fit.

Here is current `master` with old benchmark version:
```
[ 75.00%] ··· Running (ctors.SeriesConstructors.time_series_constructor--).
[100.00%] ··· ctors.SeriesConstructors.time_series_constructor                                                                                                   4/40 failed
[100.00%] ··· ===================================== =============== ============= ============== =============
              --                                                        with_index / dtype
              ------------------------------------- ----------------------------------------------------------
                             data_fmt                False / float   False / int   True / float    True / int
              ===================================== =============== ============= ============== =============
                      <function gen_of_str>            130±0.9μs       116±6μs        failed         failed
                     <function gen_of_tuples>           113±3μs        112±20μs       failed         failed
              ===================================== =============== ============= ============== =============
```
And with the fixed benchmarks, we see the existing ones falsely report a `40x` speedup:
```
[ 50.00%] ··· ===================================== =============== ============= ============== ============
              --                                                        with_index / dtype
              ------------------------------------- ---------------------------------------------------------
                             data_fmt                False / float   False / int   True / float   True / int
              ===================================== =============== ============= ============== ============
                      <function gen_of_str>            4.61±0.1ms    4.21±0.07ms       n/a           n/a
                     <function gen_of_tuples>          3.39±0.1ms    3.43±0.07ms       n/a           n/a
              ===================================== =============== ============= ============== ============
```

Additionally, this PR resolves a few failing `asv` tests that I introduced in the first iteration.

- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry
