Merge bitcoin/bitcoin#24925: refactor: make GetRand a template, remove GetRandInt

ab1ea29ba1 refactor: make GetRand a template, remove GetRandInt (pasta)

Pull request description:

  makes GetRand a template for which any integral type can be used, where the default behavior is to return a random integral up to the max of the integral unless a max is provided.
  This simplifies a lot of code from GetRand(std::numeric_limits<uint64_t>::max() -> GetRand<uint64_t>()

ACKs for top commit:
  laanwj:
    Code review ACK ab1ea29ba1

Tree-SHA512: db5082a0e21783389f1be898ae73e097b31ab48cab1a2c0e29348a4adeb545d4098193aa72a547c6baa6e8205699aafec38d6a27b3d65522fb3246f91b4daae9

src/init.cpp

@@ -1280,8 +1280,8 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     assert(!node.banman);
     node.banman = std::make_unique<BanMan>(gArgs.GetDataDirNet() / "banlist", &uiInterface, args.GetIntArg("-bantime", DEFAULT_MISBEHAVING_BANTIME));
     assert(!node.connman);
-    node.connman = std::make_unique<CConnman>(GetRand(std::numeric_limits<uint64_t>::max()),
-                                              GetRand(std::numeric_limits<uint64_t>::max()),
+    node.connman = std::make_unique<CConnman>(GetRand<uint64_t>(),
+                                              GetRand<uint64_t>(),
                                               *node.addrman, *node.netgroupman, args.GetBoolArg("-networkactive", true));
 
     assert(!node.fee_estimator);