License DB detects no licenses for majority of Nuget packages

Summary

License DB detects no license for many Nuget packages, including the following:

• Microsoft.ChakraCore (MIT); see #385173 (comment 1295566898)
• Remotion.Linq (Apache-2.0); see #385173 (comment 1295549037)

Test project shows also many Nuget packages with unknown license.

Possible fixes

There is a similar issue with Maven packages, the case maybe in the detection logic

Implementation Plan

Iteration 1

• Extend nuget license classification to support GitHub URLs and validate that Microsoft.ChakraCore is fixed

Iteration 2

• Extend nuget license classification to support HTML and validate that Remotion.Linq is fixed

Iteration 3

• Log nuget classification results

Iteration 4

• Rewrite GitHub URLS to get raw text content

Iteration 5

• Strip HTML tags in ClassifyURL

Iteration 6

• Dynamically generate URLs with different variations in urlcache.go