Minimalistic setup.py

[ataymano]

Minimalistic setup.py allowing to install util package (under "omniparser" name).

• util -> omniparser
• A lot of internals still exposed
• import takes a while because of paddleocr loading (I see bunch of other references that will be broken if it will be moved to Omniparser state, so probably in next PRs)

[yadong-lu]

Hey @ataymano, thanks for the pr. I think the folder name change of util/ maybe breaking to some of the script in omnitool. Have you checked it? Thanks