BREAKING CHANGE: Add contract versioning

[whoabuddy]

⚠️Breaking Change⚠️

This PR contains a breaking change to set up the data structure for multiple versions of CityCoins contracts.

The structure allows enough flexibility that this should be the preferred format moving forward.

What is changing?

Routes and Paths

Any routes that involve querying a city now start with :version/:cityname instead of the route category.

Before	After
/activation/get-activation-block/mia	/v1/mia/activation/get-activation-block
/mining/get-mining-stats-at-block/mia/57934	/v1/mia/mining/get-mining-stats-at-block/57934
/stacking/get-stacker-at-cycle/mia/15/1848	/v1/mia/stacking/get-stacker-at-cycle/15/1848

CityConfig Definition

In the previous version the CityConfig object represented a single set of contracts. This refactors the code to allow for:

• a version number, used as a key in the CityVersions object
• a CityConfig per version, returned by getCityConfig()
• updates to getCityConfig() to pass the version parameter
• updates to getCityConfig() error handling to pass response if not found
• individual interfaces per contract type (auth, core, token)

What is left to do?

• [x] update routes
• [x] update getCityConfig()
• [x] update handlers
• [x] update README
• [x] update landing page
• [x] verify docs are correct
• [x] update OpenAPI spec
• [x] update versioning

[whoabuddy]

Merging this into develop to fit in a few bug fixes and new endpoints before the release!

To test the new version, it will be available at https://citycoins-api.citycoins.workers.dev/