Promote API version 2 to supported (#4803)

* Promote API version 2 to supported

* Switch command line to API version 1

* Fix LedgerRequestRPC test

* Remove obsolete tx_account method

This method is not implemented, the only parts which are removed are related to command-line parsing

* Fix RPCCall test

* Reduce diff size, small test improvements

* Minor fixes

* Support for the mold linker

* [fold] handle case where both mold and gold are installed

* [fold] Use first non-default linker

* Fix TransactionEntry_test

* Fix AccountTx_test

---------

Co-authored-by: seelabs <scott.determan@yahoo.com>

src/test/rpc/LedgerRequestRPC_test.cpp

@@ -24,6 +24,8 @@
 #include <ripple/rpc/impl/RPCHelpers.h>
 #include <test/jtx.h>
 
+#include <functional>
+
 namespace ripple {
 
 namespace RPC {
@@ -263,7 +265,7 @@ public:
     }
 
     void
-    testBadInput()
+    testBadInput(unsigned apiVersion)
     {
         using namespace test::jtx;
         Env env{*this};
@@ -287,9 +289,9 @@ public:
         // the purpose in this test is to force the ledger expiration/out of
         // date check to trigger
         env.timeKeeper().adjustCloseTime(weeks{3});
-        result = env.rpc("ledger_request", "1")[jss::result];
+        result = env.rpc(apiVersion, "ledger_request", "1")[jss::result];
         BEAST_EXPECT(result[jss::status] == "error");
-        if (RPC::apiMaximumSupportedVersion == 1)
+        if (apiVersion == 1)
         {
             BEAST_EXPECT(result[jss::error] == "noCurrent");
             BEAST_EXPECT(
@@ -357,7 +359,8 @@ public:
     {
         testLedgerRequest();
         testEvolution();
-        testBadInput();
+        test::jtx::forAllApiVersions(
+            std::bind_front(&LedgerRequestRPC_test::testBadInput, this));
         testMoreThan256Closed();
         testNonAdmin();
     }