feat(v2.0.0): BREAKING CHANGES: updated all FNs to use object parameters, removed deprecated functions, updated tests

[JJ-Cro]

feat(): removed all deprecated functions, updated all FNs to use object parameters

Breaking Changes:

This PR finalises breaking changes planned a while back (see #88). Any REST API functions that had request properties as individual function parameters, will now only accept an object with the expected request parameters.

While we try to avoid breaking changes where possible, this is one that we saw as necessary to improve maintainability. Especially as new parameters are added to existing endpoints, introducing complexity in handling multiple separate parameters if some were optional.

The easiest way to address these changes it to look for any API calls where parameters are passed individually, for example:

api.setIsolatedMode('automatic', 'CONTRACTS')

Update the parameters to pass as an object instead:

api.setIsolatedMode({
  isoMode: 'automatic',
  type: 'MARGIN',
})

If you're not sure about the property names in the request object, refer to the OKX API documentation or the REST client. A convenient clickable list of endpoints can be found here:
https://github.com/tiagosiebler/okx-api/blob/master/docs/endpointFunctionList.md#how-to-use-table

If you're not already using it, typescript is highly recommended since it will catch any mistakes before you run your code.

[tiagosiebler]

Could also start doing the api error code enum, but not in this PR. In future...