Add sweepable estimator to NER

[zewditu]

We are excited to review your PR.

So we can do the best job, please check:

• [ ] There's a descriptive title that will make sense to other developers some time from now.
• [ ] There's associated issues. All PR's should have issue(s) associated - unless a trivial self-evident change such as fixing a typo. You can use the format Fixes #nnnn in your description to cause GitHub to automatically close the issue(s) when your PR is merged.
• [ ] Your change description explains what the change does, why you chose your approach, and anything else that reviewers should know.
• [ ] You have included any necessary tests in the same PR.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (9f4a389) 68.80% compared to head (d67a232) 68.80%. Report is 5 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #6965 +/- ## ========================================== - Coverage 68.80% 68.80% -0.01% ========================================== Files 1249 1249 Lines 249644 249686 +42 Branches 25481 25485 +4 ========================================== + Hits 171780 171797 +17 - Misses 71273 71294 +21 - Partials 6591 6595 +4 ``` | [Flag](https://app.codecov.io/gh/dotnet/machinelearning/pull/6965/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | Coverage Δ | | |---|---|---| | [Debug](https://app.codecov.io/gh/dotnet/machinelearning/pull/6965/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `68.80% <ø> (-0.01%)` | :arrow_down: | | [production](https://app.codecov.io/gh/dotnet/machinelearning/pull/6965/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `63.27% <ø> (-0.01%)` | :arrow_down: | | [test](https://app.codecov.io/gh/dotnet/machinelearning/pull/6965/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet) | `88.41% <ø> (-0.01%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet#carryforward-flags-in-the-pull-request-comment) to find out more. [see 15 files with indirect coverage changes](https://app.codecov.io/gh/dotnet/machinelearning/pull/6965/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dotnet)