Always pull the latest version of lombok and make it overridable by user config

[EternalWind]

• Removed the lombok.jar pre-packaged with the extension.
• By default, pull the latest version of lombok from lombok's official website if no lombok.jar is present upon activation.
• Enabled users to supply their desired version of lombok by specifying the path to it with "vscode-lombok.lombokPath" overriding the lombok downloaded by default.

[ghost]

All CLA requirements met.

[testforstephen]

@EternalWind thanks for your interest in improving this extension. Since [email protected] starts to provide the built-in lombok support from that extension, where it also has a PR redhat-developer/vscode-java#2550 to embed a lombok.jar in itself, so we're considering deprecating the lombok.jar in vscode-lombok extension. Instead, vscode-lombok extension will convert the lombok syntax sugar into code actions, and help you easily generate the annotation code into your source files.