Add baggage injection library

[vincentfree]

Create a new baggage injection library that makes baggage injection and extraction easy for adding random key value pairs.

background

For a feature called value chains which is based on service graphs, labels set for identifying which services belong to 1 value chain reduces the complexity of service graphs in large companies.

When traversing a service graph based on a system that handles thousands of applications, a label that adds context for a subset of applications makes sense.

The baggage standard: https://www.w3.org/TR/baggage/ is a perfect solution for value chain label propogation.