Feature - Remove RESTv1 in RESTv2

[vigan-abd]

Description:

This PR removes api/v1 usage in RESTv2 class. Some methods were redundant since v2 implementations already existed and some methods were rewritten by using only v2 calls!

NOTE! This PR depends in on https://github.com/bitfinexcom/bfx-api-node-models/pull/60 and https://github.com/bitfinexcom/bfx-api-mock-srv/pull/44 PRs

Breaking changes:

• removed _rest1 in RESTv2
• removed _makePublicLegacyRequest in RESTv2
• removed _makeAuthLegacyRequest in RESTv2
• removed accountInfo in RESTv2 since accountSummary already exists in RESTv2 implementation
• removed balances in RESTv2 since wallets already exists in RESTv2 implementation
• adjusted accountSummary to use api endpoint mentioned in docs
• symbolDetails migrated to use api/v2, result format changes
• accountFees migrated to use api/v2, result format changes
• closePosition migrated to use api/v2 calls only
• keyPermissions migrated to use api/v2, result format changes

New features:

• added SymbolDetails model in corresponding function result
• added TransactionFee model in corresponding function result
• added AccountSummary model in corresponding function result

Fixes:

• adjusted accountSummary to use api endpoint mentioned in docs

PR status:

• [x] Version bumped
• [x] Change-log updated
• [ ] Tests added or updated
• [x] Documentation updated