Feature Request: `dvc exp push --queued` to push queued experiments

[prcastro]

I want to run my experiments in my CI/CD pipeline, so I can use remote compute resources and also share the results with my team. My intended workflow is the following:

# Create a branch for the experiments
$ git checkout -b my-experiment

# Queue up some experiments
$ dvc exp run --name my-experiment --queue "param=1,2,3,4"

# Push the queue. This is the FEATURE REQUEST.
$ dvc exp push --queued

# Open a PR
$ git commit -am "Experiment description" --allow-empty
$ git push origin my-experiment
$ gh pr create --fill

Then a CI/CD pipeline will basically run:

# Before this command we check if there are any experiments queued
# ...
# Run all the experiments and show results
$ dvc exp run --run-all
$ dvc exp show

After reading and deciding an experiment to apply, I run locally:

# Pull experiment results and apply the best one
$ dvc exp pull
$ dvc apply best-experiment
$ git commit -am "Apply best parameters"
$ git push origin my-experiment

# After my team reviews the PR
$ gh pr merge