Group documentation for bias acceleration

[mitiguy]

To address issue #21711 and during review of PR #21740, a doxygen group
@name Bias acceleration functions
was added to multibody_plant.h to group the following overloaded function :

1. CalcBiasCenterOfMassTranslationalAcceleration() -- Overload 1 of 2.
2. CalcBiasCenterOfMassTranslationalAcceleration() -- Overload 2 of 2.

In a subsequent PR (ASAP), also group the following.

1. CalcBiasTranslationalAcceleration()
2. CalcBiasSpatialAcceleration()
3. CalcBiasTerm() -- albeit this is somewhat different in spirit.

**Alternatives that were tried **
Documentation for each overload was tried separately (without an @name group) and the amount of repeated documentation was significant. The reviewer (Sherm) preferred consolidating common documentation into an @name group with a subsequent PR to group other related documentation.

Additional context
Also discussed: consider a subsequent PR to consolidate Jacobian functions in multibody_plant.h into their own @name group, e.g.,

1. CalcJacobianSpatialVelocity().
2. CalcJacobianAngularVelocity().
3. CalcJacobianTranslationalVelocity().
4. CalcJacobianPositionVector().
5. CalcJacobianCenterOfMassTranslationalVelocity() -- Overload 1 of 2.
6. CalcJacobianCenterOfMassTranslationalVelocity() -- Overload 2 of 2.