[detection] move padding removal directly to detection

[felixdittrich92]

This PR:

• make padding removal part of the detection predictor
• make the detection_predictor standalone (before the user has to do the padding removal on it's on which is not correct)
• update API now the detection results are the same with ocr_predictor and detection_predictor

Any feedback is welcome :hugs:

CC @ArsalanYounus007 @yumikim381

Note: again API will fail until merged ^^

ref.: https://github.com/mindee/doctr/discussions/1619 https://github.com/mindee/doctr/issues/1622

[codecov[bot]]

Codecov Report

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

Project coverage is 96.38%. Comparing base (9c92f5c) to head (c1d6a36).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1627 +/- ## ========================================== + Coverage 96.25% 96.38% +0.13% ========================================== Files 163 164 +1 Lines 7707 7716 +9 ========================================== + Hits 7418 7437 +19 + Misses 289 279 -10 ``` | [Flag](https://app.codecov.io/gh/mindee/doctr/pull/1627/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mindee) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/mindee/doctr/pull/1627/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mindee) | `96.38% <100.00%> (+0.13%)` | :arrow_up: | 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=mindee#carryforward-flags-in-the-pull-request-comment) to find out more.

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[felixT2K]

Included mypy fixes for new version