prepare_registration fixes for multi contributors

Adds two slightly different versions of prepare_registration: one that
works with the existing 4-person registrations (used up to the hard
fork), and one that produces HF19 amount-based registrations.

This also overhauls the questions to be a bit nicer to input;
specifically:

- allow "max" and "min" as stake amount options, and make "max" the
  default.
- eliminate the "do you want to contribute the whole stake?" question
  entirely.  We instantly figure that out if you choose "max" (or enter
  the 15000 manually).
- eliminate the "how many contributors?" question.  Instead we just keep
  taking additional contributors until you stop entering them.
- move the fee to later, after you've provided contributor info (if not
  a full stake).

There is, unfortunately, a *huge* amount of duplication here: I copy and
pasted the entire HF18 registration code and just eliminated the
portions parts of it.  This is temporary: as soon as we are into HF19 we
can eliminate the HF18 version entirely.

src/cryptonote_core/service_node_list.cpp

@@ -3924,9 +3924,11 @@ namespace service_nodes
           tr("Run this command in the operator's wallet"),
           cryptonote::get_account_address_as_str(nettype, false, reg.reserved[0].first));
 
-    cmd += "register_service_node";
-    cmd += tools::join(" ", args);
-    cmd += fmt::format(" {} {} {}", reg.hf, tools::type_to_hex(reg.service_node_pubkey), tools::type_to_hex(reg.signature));
+    cmd += fmt::format("register_service_node {} {} {} {}",
+            tools::join(" ", args),
+            reg.hf,
+            tools::type_to_hex(reg.service_node_pubkey),
+            tools::type_to_hex(reg.signature));
 
     if (make_friendly && reg.uses_portions)
     {

src/cryptonote_core/service_node_rules.cpp

@@ -1,3 +1,4 @@
+#include "common/string_util.h"
 #include "cryptonote_config.h"
 #include "cryptonote_basic/hardfork.h"
 #include "common/oxen.h"
@@ -257,24 +258,30 @@ static bool get_portions_from_percent(double cur_percent, uint64_t& portions) {
   return true;
 }
 
+std::optional<double> parse_fee_percent(std::string_view fee)
+{
+  if (tools::ends_with(fee, "%"))
+    fee.remove_suffix(1);
+
+  double percent;
+  try {
+    percent = boost::lexical_cast<double>(fee);
+  } catch(...) {
+    return std::nullopt;
+  }
+
+  if (percent < 0 || percent > 100)
+    return std::nullopt;
+
+  return percent;
+}
+
 bool get_portions_from_percent_str(std::string cut_str, uint64_t& portions) {
 
-  if(!cut_str.empty() && cut_str.back() == '%')
-  {
-    cut_str.pop_back();
-  }
+  if (auto pct = parse_fee_percent(cut_str))
+    return get_portions_from_percent(*pct, portions);
 
-  double cut_percent;
-  try
-  {
-    cut_percent = boost::lexical_cast<double>(cut_str);
-  }
-  catch(...)
-  {
-    return false;
-  }
-
-  return get_portions_from_percent(cut_percent, portions);
+  return false;
 }
 
 } // namespace service_nodes

src/cryptonote_core/service_node_rules.h

@@ -290,6 +290,8 @@ uint64_t     get_locked_key_image_unlock_height(cryptonote::network_type nettype
 // Returns lowest x such that (staking_requirement * x/STAKING_PORTIONS) >= amount
 uint64_t get_portions_to_make_amount(uint64_t staking_requirement, uint64_t amount, uint64_t max_portions = cryptonote::old::STAKING_PORTIONS);
 
+std::optional<double> parse_fee_percent(std::string_view fee);
+
 bool get_portions_from_percent_str(std::string cut_str, uint64_t& portions);
 
 }

src/daemon/rpc_command_executor.h

@@ -186,6 +186,8 @@ public:
   bool print_sr(uint64_t height);
 
   bool prepare_registration(bool force_registration=false);
+  // TODO FIXME: remove immediately after HF19 happens
+  bool prepare_registration_hf18(cryptonote::hf hf_version, bool force_registration);
 
   bool print_sn(const std::vector<std::string> &args);
 

src/rpc/core_rpc_server_commands_defs.h

@@ -634,7 +634,7 @@ namespace rpc {
       bool mainnet;                         // States if the node is on the mainnet (`true`) or not (`false`).
       bool testnet;                         // States if the node is on the testnet (`true`) or not (`false`).
       bool devnet;                          // States if the node is on the devnet (`true`) or not (`false`).
-      std::string nettype;                  // Nettype value used.
+      std::string nettype;                  // Network type as a string ("mainnet", "testnet", "devnet", or "fakechain").
       std::string top_block_hash;           // Hash of the highest block in the chain.
       std::string immutable_block_hash;     // Hash of the highest block in the chain that can not be reorganized.
       uint64_t cumulative_difficulty;       // Cumulative difficulty of all blocks in the blockchain.