feat: integrate got-ocr2.0 as image reader

[phv2312]

Description

• Integrate the got-ocr2.0 OCR as image reader
• New extension manager for easily switch between different supported loaders
• Also, thanks @cin-jimmy for his suggestion on github stale (issue)

Type of change

• New features (non-breaking change).
• Bug fix (non-breaking change).
• Breaking change (fix or feature that would cause existing functionality not to work as expected).

Checklist

• I have performed a self-review of my code.
• I have added thorough tests if it is a core feature.
• There is a reference to the original bug report and related work.
• I have commented on my code, particularly in hard-to-understand areas.
• The feature is well documented.

[cin-niko]

@phv2312, can you add a docker-compose file (allow choose the docker image for OCR service)? I think it will help people test more easily.

[phv2312]

Hi @taprosoft @cin-niko. Sorry for no update for long time. Can you help to review this PR again

[phv2312]

Hi @cin-niko and @taprosoft . I have updated according to niko's comments and rebased from the latest master already.
Can you help to check this PR again ?

[cin-niko]

@phv2312 Overall is good. But it seems that setting the loader for extensions feature doesn't work.
For example:

• Set pdf loader in Settings -> Retrieval Settings -> File loader: Work
• Set pdf loader in Settings -> Loader settings -> Loader .pdf: Doesn't work

[taprosoft]

@phv2312 sorry for the late comment. Overall the logic is fine but the current settings UI is a bit cluttered. I will push a small change to improve this prior to merging.

[heapsoftware]

Need OCR for PDFs working as well, when I upload a PDF which is created by a scanner that scans in pages, it puts the scanned pages into a multi-page PDF. Need to be able to upload the PDF, which then it does an OCR to extract the text and use that extracted text for reasoning.