Support proxy server download song. (#1911)

[Tunglies]

Title

Http request proxy server support.

Description

Add proxy server support for requesting bandcamp, piped, sliderkz, genius, musixmatch, metadata.

Related Issue

#1911

Motivation and Context

Downloading music from region likes in China needs proxy server.

How Has This Been Tested?

Build from source and run as expected.

Screenshots (if appropriate)

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have read the CONTRIBUTING document
• I have read the CORE VALUES document
• I have added tests to cover my changes
• All new and existing tests passed