libstore: Correct getUri methods for all stores

Previously `getUri` didn't include store query parameters,
`ssh-ng` didn't include any information at all and the local
store didn't have the path:

```
$ nix store info --store "local?root=/tmp/aaa&require-sigs=false"
Store URL: local
Version: 2.31.0
Trusted: 1
$ nix store info --store "ssh-ng://localhost?remote-program=nix-daemon"
Store URL: ssh-ng://
Version: 2.31.0
Trusted: 1
$ nix store info --store "ssh://localhost?remote-program=nix-store"
Store URL: ssh://localhost
```

This commit changes this to:

```
$ nix store info --store "local?root=/tmp/aaa&require-sigs=false"
Store URL: local?require-sigs=false&root=/tmp/aaa
Version: 2.31.0
Trusted: 1
$ nix store info --store "ssh-ng://localhost?remote-program=nix-daemon"
Store URL: ssh-ng://localhost?remote-program=nix-daemon
Version: 2.31.0
Trusted: 1
$ nix store info --store "ssh://localhost?remote-program=nix-store"
Store URL: ssh://localhost?remote-program=nix-store
```

src/libstore/include/nix/store/store-api.hh

@@ -126,6 +126,19 @@ struct StoreConfig : public StoreDirConfig
         return "";
     }
 
+    /**
+     * Get overridden store reference query parameters.
+     */
+    StringMap getQueryParams() const
+    {
+        auto queryParams = std::map<std::string, AbstractConfig::SettingInfo>{};
+        getSettings(queryParams, /*overriddenOnly=*/true);
+        StringMap res;
+        for (const auto & [name, info] : queryParams)
+            res.insert({name, info.value});
+        return res;
+    }
+
     /**
      * An experimental feature this type store is gated, if it is to be
      * experimental.

src/libstore/legacy-ssh-store.cc

@@ -90,7 +90,9 @@ ref<LegacySSHStore::Connection> LegacySSHStore::openConnection()
 
 std::string LegacySSHStore::getUri()
 {
-    return *Config::uriSchemes().begin() + "://" + config->authority.to_string();
+    return ParsedURL{
+        .scheme = *Config::uriSchemes().begin(), .authority = config->authority, .query = config->getQueryParams()}
+        .to_string();
 }
 
 std::map<StorePath, UnkeyedValidPathInfo> LegacySSHStore::queryPathInfosUncached(const StorePathSet & paths)

src/libstore/local-store.cc

@@ -16,6 +16,7 @@
 #include "nix/store/posix-fs-canonicalise.hh"
 #include "nix/util/posix-source-accessor.hh"
 #include "nix/store/keys.hh"
+#include "nix/util/url.hh"
 #include "nix/util/users.hh"
 #include "nix/store/store-open.hh"
 #include "nix/store/store-registration.hh"
@@ -440,7 +441,13 @@ LocalStore::~LocalStore()
 
 std::string LocalStore::getUri()
 {
-    return "local";
+    std::ostringstream oss;
+    oss << *config->uriSchemes().begin();
+    auto queryParams = config->getQueryParams();
+    if (!queryParams.empty())
+        oss << "?";
+    oss << encodeQuery(queryParams);
+    return std::move(oss).str();
 }
 
 int LocalStore::getSchema()

src/libstore/ssh-store.cc

@@ -43,7 +43,9 @@ struct SSHStore : virtual RemoteStore
 
     std::string getUri() override
     {
-        return *Config::uriSchemes().begin() + "://" + host;
+        return ParsedURL{
+            .scheme = *Config::uriSchemes().begin(), .authority = config->authority, .query = config->getQueryParams()}
+            .to_string();
     }
 
     // FIXME extend daemon protocol, move implementation to RemoteStore
@@ -66,8 +68,6 @@ protected:
 
     ref<RemoteStore::Connection> openConnection() override;
 
-    std::string host;
-
     std::vector<std::string> extraRemoteProgramArgs;
 
     SSHMaster master;