(android/ios): support request headers for iOS/android

[RonnieRen]

this is the pr for the original pr: https://github.com/apache/cordova-plugin-inappbrowser/pull/363/files merge the latest changes & resolve the conflicts

Platforms affected

Motivation and Context

Description

support the header parameters

Testing

Checklist

• [x] I've run the tests to see all new and existing tests pass
• [ ] I added automated test coverage as appropriate for this change
• [x] Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• [ ] If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• [x] I've updated the documentation if necessary

[RonnieRen]

@janpio could you take a look at pr?