Strip transparent data from GetBlockNullifiers response

[nuttycom]

GetBlockNullifiers was not clearing the vin and vout fields from transactions, causing transparent data to leak through a method that should only return shielded nullifier information.

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• Relevant documentation for this PR has to be completed before the PR can be merged
• A test plan for the PR must be documented in the PR notes and included in the test plan for the next regular release

As a note, all CI tests need to be passing and all appropriate code reviews need to be done before this PR can be merged

[LarryRuane]

Looks good. I verified that GetBlockRangeNullifiers is already correct; it doesn't return the transparent parts (so the analogous change isn't needed there). My only suggestion is including the following (I'd say in the same commit) to test the changes (this fails without this PR):

diff

--- a/smoke-test.bash
+++ b/smoke-test.bash
@@ -186,6 +186,32 @@ expected='{
 }'
 compare "$expected" "$actual"
 
+# Same as previous except with only the nullifiers remaining
+echo GetblockNullifiers 663190 ...
+actual=$(gp GetBlockNullifiers '{"height":663190}')
+expected='{
+  "height": "663190",
+  "hash": "rnAgBry+ZWhKw+LSrWfMDFuLalVQVq7u/QyJAPFae1Y=",
+  "prevHash": "xOcqS6kNnE4yHGnLcvi1LMOqh9iY3ynEGpUTraSKpvQ=",
+  "time": 1,
+  "vtx": [
+    {
+      "txid": "jZno30toIVWj7Np39zJPgvdkZnTAGn4L8Mgcn8t79zo="
+    },
+    {
+      "index": "1",
+      "txid": "H0nPz83r1cuQhdn/LvvNqHEh3aE/LHkRE/zy55uoIQg=",
+      "spends": [
+        {
+          "nf": "xrZLCu+Kbv6PXo8cqM+f25Hp55L2cm95bM68JwUnDHg="
+        }
+      ]
+    }
+  ],
+  "chainMetadata": {}
+}'
+compare "$expected" "$actual"
+
 # force a reorg with the transactions now in 663195
 echo -n test: StageBlocksCreate blocks 663180 to 663179 ...
 gt StageBlocksCreate '{"height":663180,"count":100}'

[LarryRuane]

To save you the trouble, I went ahead and force-pushed to add the test; that's all I changed. Hope that's okay.