crypto: Add crypto.getEngines()

[shigeki]

This adds a new api to show the list of loaded engines of OpenSSL.
It also includes the test of dynamic engine for crypto.setEngine() and fixes missed test coverages as discussed in #10786.

A test engine is built from test/fixtures/openssl_test_engine/ by adding a new target in node.gyp, but fipsld seems to have an error with linking the test engine with libcrypto.a so that a dynamic engine test is skipped in FIPS mode.

I've already made several CI tests and found that tests on Windows and arm were failed because test engine files were lost in CI environment. They can be solved by includingRelease\node_test_engine.dll in Windows tests and out/Release/libnode_test_engine.so in arm tests in binary/binary.tar.gz and binary/binary.tar.xz . I would like ask someone in @nodejs/build to help it.

In my local environments, tests in Win and arm are fine.

CC @nodejs/crypto and @jasnell

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

Affected core subsystem(s)

crypto