[FEATURE]:add oceanbase oracle mode xa connect

[xxsc0529]

[description] The current version does not support XA linking in oceanbase oracle mode.With the support of OceanBase-Client for OceanBase Oracle XA links, the judgment of OceanBase Oracle mode is added when obtaining Xaconnect. close #6235 [TEST] Please see the specific test com/alibaba/druid/bvt/pool/xa/OceanBaseOracleXATest.java Since OceanBase Oracle is owned by the Enterprise Edition and is not open to the public, the test results are pasted below reference:https://github.com/oceanbase/obconnector-j/blob/master/src/test/java/com/oceanbase/jdbc/OceanbaseOracleXATest.java [NOTE] If you use an XA link in oceanbase oracle mode, you must set the jdbc url connection string parameter. useServerPrepStmts=true is explained in the test class

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