Add referrer header to requests

[lllwvlvwlll]

This feature will implement an optional referrer field to all requests. The value will default when not populated.

[picarodias]

Instructions from Slack (13.dec.21)

• We're probably going to need to restructure the code a bit since there is already an optional parameter.
• So it will need to accept an optional configuration object instead.
• We can default it to 'dora-ts' with the ability to override.
• This merge pattern is how I recommend implementing:
  • https://github.com/CityOfZion/props/blob/develop/sdk/src/Collection.ts#L10

[revett]

@lllwvlvwlll Is this issue still relevant?

[lllwvlvwlll]

Its still relevant and helpful for tagging api usage.