Add DNS API plugin for Oracle Cloud Infrastructure DNS Service

This plugin is has noticeably more required fields than most
other plugins due to the requirement that all requests to
the OCI REST API must be cryptographically signed by the client
using the draft standard proposed in draft-cavage-http-signatures-08[1].

The OCI specific implementation details of the draft standard are
documented in the Developer Guide[2].

NOTE: there is maximum allowed clock skew of five minutes between the
client and the API endpoint. Requests will be denied if the skew is
greater.

This PR also includes a minor tweak to the Solaris job in the DNS
workflow so that it uses the pre-installed GNU tools, curl and OpenSSL 1.1.1.
Without these changes, the signature generation function does not
work on Solaris.

[1]: https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures-08
[2]: https://docs.oracle.com/en-us/iaas/Content/API/Concepts/signingrequests.htm#five

Signed-off-by: Avi Miller <avi.miller@oracle.com>

.github/workflows/DNS.yml

@@ -59,7 +59,7 @@ jobs:
       run: cd .. && git clone https://github.com/acmesh-official/acmetest.git  && cp -r acme.sh acmetest/
     - name: Set env file
       run: |
-        cd ../acmetest 
+        cd ../acmetest
         if [ "${{ secrets.TokenName1}}" ] ; then
           echo "${{ secrets.TokenName1}}=${{ secrets.TokenValue1}}" >> env.list
         fi
@@ -75,7 +75,7 @@ jobs:
         if [ "${{ secrets.TokenName5}}" ] ; then
           echo "${{ secrets.TokenName5}}=${{ secrets.TokenValue5}}" >> env.list
         fi
-        echo "TEST_DNS_NO_WILDCARD" >> env.list 
+        echo "TEST_DNS_NO_WILDCARD" >> env.list
         echo "TEST_DNS_SLEEP" >> env.list
     - name: Run acmetest
       run: cd ../acmetest && ./rundocker.sh  testall
@@ -226,8 +226,10 @@ jobs:
     - uses: vmactions/solaris-vm@v0.0.3
       with:
         envs: 'TEST_DNS TestingDomain TEST_DNS_NO_WILDCARD TEST_DNS_SLEEP CASE TEST_LOCAL DEBUG ${{ secrets.TokenName1}} ${{ secrets.TokenName2}} ${{ secrets.TokenName3}} ${{ secrets.TokenName4}} ${{ secrets.TokenName5}}'
-        prepare: pkgutil -y -i socat curl
+        prepare: pkgutil -y -i socat
         run: |
+          pkg set-mediator -v -I default@1.1 openssl
+          export PATH=/usr/gnu/bin:$PATH
           if [ "${{ secrets.TokenName1}}" ] ; then
             export ${{ secrets.TokenName1}}=${{ secrets.TokenValue1}}
           fi
@@ -245,5 +247,3 @@ jobs:
           fi
           cd ../acmetest
           ./letest.sh
-
-