Error Message Could be Improved for `http_file`

Description of the issue

The error messages when referencing an http_file in the srcs section can be cryptic and could be improved to help the user fix the problem.

Repro

# WORKSPACE
http_file(
    name = "available_port_finder",
    downloaded_file_path = "AvailablePortFinder.java",
    urls = [
        "https://svn.apache.org/viewvc/camel/trunk/components/camel-test/src/main/java/org/apache/camel/test/AvailablePortFinder.java?revision=1232764&view=co",
    ],
)

# BUILD
java_library(
    name = "available_port_finder",
    srcs = [
        "@available_port_finder//:AvailablePortFinder.java",
    ],
)

Then run:

$ bazel build //:available_port_finder

From here, one gets this message:

ERROR: /usr/local/home/aryehh/Development/code/BUILD.bazel:11:13: no such package '@available_port_finder//': BUILD file not found in directory '' of external repository @available_port_finder. Add a BUILD file to a directory to mark it as a package. and referenced by '//:available_port_finder'
ERROR: Analysis of target '//:available_port_finder' failed; build aborted: Analysis failed
INFO: Elapsed time: 0.172s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (1 packages loaded, 0 targets configured)
FAILED: Build did NOT complete successfully (1 packages loaded, 0 targets configured)

The way to fix the issue is to put "@available_port_finder//file" in the srcs attribute of the java_library.

Expected Behavior

Bazel tells the user to reference file instead of the downloaded_file_path (name of the file)

---

Which operating system are you running Bazel on?

Debian Rodete

What is the output of bazel info release?

bazel 5.3.1

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

release 5.3.1