Add built-in SocketCahnnelProvider, implementing round-robin between several tarantool instances

[sharonovd]

Use-case: tarantool is deployed as a geo-distributed cluster, and when one DC goes down, application must switch to reserve DC with minimal service disruption.

Proposal: add built-in Provider which would take several connection URI's as a config, and would quickly try to establish connection to them in a circle, returning the first succesful one.
Edge-case: if all URIs are unavailable, return error.

Such Provider could be used straight-away in described use-case, and would be also useful as a demo of more advanced connection strategies.

[Totktonada]

• Similar tarantool-python issue: Reconnection strategy - round-robin between instances tarantool-python#106
• Similar go-tarantool issue: Reconnection strategy - round-robin between instances go-tarantool#68

[Totktonada]

@sharonovd It is unclear whether it is needed for org.tarantool.TarantoolConnection (basic connector functionality) or java.sql.Connection (JDBC).

[sharonovd]

@Totktonada basic