WIP: Simplify dbus service name creation

Non-indexed dbus service names for instance based daemons got
deprecated. It is expected, that xyz.openbmc_project.State.Host0 and
xyz.openbmc_project.State.Chassis0 exist on every single-host platform.

Remove the multi-host check, and directly return an index based dbus
service name.

Tested: Manually checking if dbus service is picking up the requested
ResetType / state transition interface.

Before POST:
```
$ busctl introspect xyz.openbmc_project.State.Host0 \
/xyz/openbmc_project/state/host0

xyz.openbmc_project.State.Host                   interface -         -
...
.RequestedHostTransition                         property  s         "xyz.openbmc_project.State.Host.Transition.Off"
...
```

POST request:
```
$ curl -v -k  POST
'https://'"${BMC}"':'"${BMC_WEBPORT}"'/redfish/v1/Systems/system/Actions/ComputerSystem.Reset' \
    -H 'X-Auth-Token: '"$BMCWEB_SESSION_TOKEN"'' \
    -H "Content-Type: application/json" -d {"ResetType":"On"}
```
After POST:
```
$ busctl introspect xyz.openbmc_project.State.Host0 \
/xyz/openbmc_project/state/host0

.RequestedHostTransition                         property  s         "xyz.openbmc_project.State.Host.Transition.On"
```
Change-Id: I5b2c37f9d6a622af0c056504e1bb6dd839fd7d14
Signed-off-by: Oliver Brewka <[email protected]>

Author: mox669

redfish-core/include/utils/systems_utils.hpp

@@ -226,13 +226,7 @@ inline sdbusplus::message::object_path getHostStateObjectPath(
 
 inline std::string getHostStateServiceName(const uint64_t computerSystemIndex)
 {
-    if constexpr (BMCWEB_EXPERIMENTAL_REDFISH_MULTI_COMPUTER_SYSTEM)
-    {
-        return std::format("xyz.openbmc_project.State.Host{}",
-                           computerSystemIndex);
-    }
-
-    return "xyz.openbmc_project.State.Host";
+    return std::format("xyz.openbmc_project.State.Host{}", computerSystemIndex);
 }
 
 inline sdbusplus::message::object_path getChassisStateObjectPath(
@@ -246,13 +240,8 @@ inline sdbusplus::message::object_path getChassisStateObjectPath(
 inline std::string getChassisStateServiceName(
     const uint64_t computerSystemIndex)
 {
-    if constexpr (BMCWEB_EXPERIMENTAL_REDFISH_MULTI_COMPUTER_SYSTEM)
-    {
-        return std::format("xyz.openbmc_project.State.Chassis{}",
-                           computerSystemIndex);
-    }
-
-    return "xyz.openbmc_project.State.Chassis";
+    return std::format("xyz.openbmc_project.State.Chassis{}",
+                       computerSystemIndex);
 }
 
 inline sdbusplus::message::object_path getControlObjectPath(