Introduce listenablefuture and failureaccess artifacts, plus Internal…

…FutureFailureAccess.

(taken over from CL 210155310 to add Maven setup)

It provides a direct access to the cause of any failures,
so we can avoid unnecessary allocation of an exception.

Design discussion: https://docs.google.com/document/d/1_RVTtztq5pqrhs0srvJWHMI7PT1tA71--iaauV2l5UA/edit

RELNOTES=Created separate `listenablefuture` and `failureaccess` artifacts, the latter containing the new `InternalFutureFailureAccess`. For more details about `listenablefuture`, see [this announcement](https://groups.google.com/d/topic/guava-announce/Km82fZG68Sw).

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=212516713

Set version number for guava-parent to 26.0.

Set version number for guava-parent to 23.6.1.

Set version number for guava-parent to 25.1.

Set version number for guava-parent to 24.1.1.

Set version number for guava-parent to 25.0.

Set version number for guava-parent to 24.1.

Set version number for guava-parent to 24.0.

Set version number for guava-parent to 23.6.

Set version number to 23.5.