refactor: merge fedot_ind into fedot as an integrated module

## Summary

Merge the codebase from [fedot_ind](https://github.com/aimclub/Fedot.Industrial) (`api`, `core`, `utils`) into `fedot/industrial` as a submodule and update imports.

## Motivation

Currently, FEDOT and Fedot.Industrial exist as separate repositories with significant overlap and monkey-patch dependencies. Merging them into a single framework will simplify maintenance, improve code reuse, and provide a unified user experience both for simple and industrial tasks.

## Guide-level explanation

> This is a structural change only, so no behavioral changes at this stage
* Move fedot_ind/ to fedot/industrial/
* Update all imports from fedot_ind.* to fedot.industrial.*
* Fix any file naming or path issues