Merge bitcoin/bitcoin#28056: rpc: doc: Added longpollid and data params to template_request

f6a2619 Added `longpollid` and `data` params to `template_request` #27998 (Rhythm Garg)

Pull request description:

  This PR will add the optional parameters `longpollid` and `data` to `template_request` as they were missing when calling `help getblocktemplate` in RPCHelpMan.

  I request the maintainers to review this and let me know about any mistakes in the descriptions of the parameters.

  This PR refers to the issue #27998

ACKs for top commit:
  ItIsOHM:
    > tACK [f6a2619](bitcoin/bitcoin@f6a2619)
  russeree:
    tACK bitcoin/bitcoin@f6a2619
  stickies-v:
    tACK f6a2619

Tree-SHA512: 6c592db59cb11b2d031ce5265c547fa296266278f6c25f96afe18a420e0d547f4d483e0f66de75d52c0c319ac1585f3558b9f70c12ef208c96ec96a51f786c6a

Author: fanquake

src/rpc/mining.cpp

@@ -566,6 +566,8 @@ static RPCHelpMan getblocktemplate()
                     {"segwit", RPCArg::Type::STR, RPCArg::Optional::NO, "(literal) indicates client side segwit support"},
                     {"str", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "other client side supported softfork deployment"},
                 }},
+                {"longpollid", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "delay processing request until the result would vary significantly from the \"longpollid\" of a prior template"},
+                {"data", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "proposed block data to check, encoded in hexadecimal; valid only for mode=\"proposal\""},
             },
             RPCArgOptions{.oneline_description="\"template_request\""}},
         },