Fuzzy autocompletion improvements for shell integration #11644

Description of the problem / feature request:

Feature Request:

The shell autocompletion feature for any shell can offload fuzzy completion
of bazel targets to fzf. Consider installing fzf
(go get -u github.com/junegunn/fzf) and run the following
command to see how it works:

bazel test $(bazel query '...' --output label | fzf)

Some visuals:

Could you please integrate the following with
the shell autocompletion scripts if possible?

# individual test selection
$ bazel test $(bazel query 'kind(".*_test", ...)' --output label | fzf)

# individual benchmark selection
$ bazel run --config=release $(bazel query 'kind(".*_binary", filter(".*_benchmark", ...))' --output label | fzf)

# run a selected binary
$ bazel run $(bazel query 'kind(".*_binary", ...)' --output label | fzf)

It'd be wild if the autocompletion scripts did this automatically.
Perhaps by adding key bindings for bazel targets too.

Example key sequences for absolute target path completion:

$ bazel run --config=release //<tab:fzf-complete-binary-target> //<tab:fzf-complete-binary-target>

$ bazel test --config=tsan //<tab:fzf-complete-test-target> //<tab:fzf-complete-test-target>

Example key sequences for relative target path completion:

$ bazel run --config=release <tab:fzf-complete-binary-target-below-current-directory> <tab:fzf-complete-binary-target-below-current-directory>

$ bazel test --config=tsan <tab:fzf-complete-test-target-below-current-directory> <tab:fzf-complete-test-target>

where each target selection list also contains //package/path/... and ... as options to select.

Feature requests: what underlying problem are you trying to solve with this feature?

I've used Bazel for several years and my number 1 feature
request would be making it super convenient for users to use bazel
without having to remember or type large paths. This improves user efficiency.
Multiply that by the number of users and you have a much faster workforce.
It's likely this may also cause people to create fine-grained Bazel dependency
graphs.

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Not a bug but a productivity enhancement.

What operating system are you running Bazel on?

Linux, Mac OS X.

What's the output of bazel info release?

release 3.3.0

If bazel info release returns "development version" or "(@Non-Git)", tell us how you built Bazel.

N/A

What's the output of git remote get-url origin ; git rev-parse master ; git rev-parse HEAD ?

N/A

Have you found anything relevant by searching the web?

Another feature request for adding fish shell integration for Bazel.
#11450

Any other information, logs, or outputs that you want to share?

N/A