Allow model_instances for MBP::CalcJacobianCenterOfMassTranslationalVelocity()

[mitiguy]

New overload for MultibodyPlant::CalcJacobianCenterOfMassTranslationalVelocity() to allow for model_instances
to resolve issue #14916.

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This change is 

[mitiguy]

Feature review +@hongkai-dai (you suggested issue #14916, feel free to redirect if needed).

Reviewable status: LGTM missing from assignee hongkai-dai, needs platform reviewer assigned, needs at least two assigned reviewers, commits need curation (https://drake.mit.edu/reviewable.html#curated-commits) (waiting on @hongkai-dai)

[hongkai-dai]

could you also add the python binding for this new function?

Reviewed 2 of 5 files at r1, 3 of 3 files at r2, 1 of 1 files at r3.
Reviewable status: needs platform reviewer assigned, needs at least two assigned reviewers, commits need curation (https://drake.mit.edu/reviewable.html#curated-commits) (waiting on @mitiguy)

[hongkai-dai]

+@sherm1 for platform review please, thanks!

Reviewable status: LGTM missing from assignee sherm1(platform), commits need curation (https://drake.mit.edu/reviewable.html#curated-commits) (waiting on @sherm1)

[sherm1]

Platform pending a few nits. I will fix those since Paul is on a long vacation.

Reviewed 2 of 5 files at r1, 3 of 3 files at r2, 1 of 1 files at r3.
Reviewable status: 2 unresolved discussions, commits need curation (https://drake.mit.edu/reviewable.html#curated-commits) (waiting on @mitiguy)

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multibody/plant/test/multibody_plant_jacobians_test.cc, line 313 at r3 (raw file):

    bodyB_ = &plant_->AddRigidBody("bodyB", bodyB_instance_, M_Bcm);
    // bodyA_ = &plant_->AddRigidBody("BodyA", M_Bcm);
    // bodyB_ = &plant_->AddRigidBody("BodyB", M_Bcm);

nit: delete dead code

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multibody/tree/multibody_tree.cc, line 2615 at r3 (raw file):

    JacobianWrtVariable with_respect_to,
    const Frame<T> &frame_A,
    const Frame<T> &frame_E,

nit: "&" misplaced

[mitiguy]

Reviewable status: commits need curation (https://drake.mit.edu/reviewable.html#curated-commits) (waiting on @hongkai-dai and @sherm1)

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multibody/plant/test/multibody_plant_jacobians_test.cc, line 313 at r3 (raw file):

Previously, sherm1 (Michael Sherman) wrote…

nit: delete dead code

Done.

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multibody/tree/multibody_tree.cc, line 2615 at r3 (raw file):

Previously, sherm1 (Michael Sherman) wrote…

nit: "&" misplaced

Done.

[sherm1]

Reviewed 2 of 2 files at r4.
Reviewable status: complete! all discussions resolved, LGTM from assignees sherm1(platform),hongkai-dai (waiting on @mitiguy)