added real UID to ActorPathBenchmarks

[Aaronontheweb]

Changes

While working on #6195 I realized that none of those ActorPaths actually have a set UID, thus we're missing that entire facet from both the parsing and serialization benchmarks.

Checklist

For significant changes, please ensure that the following have been completed (delete if not relevant):

• This change follows the Akka.NET API Compatibility Guidelines.
• This change follows the Akka.NET Wire Compatibility Guidelines.
• I have reviewed my own pull request.

Latest v1.4 Benchmarks

BenchmarkDotNet=v0.13.1, OS=Windows 10.0.19044.2251 (21H2)
AMD Ryzen 7 1700, 1 CPU, 16 logical and 8 physical cores
.NET SDK=7.0.100
  [Host]     : .NET 7.0.0 (7.0.22.51805), X64 RyuJIT
  DefaultJob : .NET 7.0.0 (7.0.22.51805), X64 RyuJIT

Method	Uid	Mean	Error	StdDev	Gen 0	Allocated
ActorPath_Parse	1	268.316 ns	1.5227 ns	1.2715 ns	0.0992	416 B
ActorPath_Concat	1	38.400 ns	0.1241 ns	0.1036 ns	0.0268	112 B
ActorPath_Equals	1	4.377 ns	0.0361 ns	0.0320 ns	-	-
ActorPath_ToString	1	50.872 ns	0.1519 ns	0.1269 ns	0.0268	112 B
ActorPath_ToSerializationFormat	1	168.876 ns	1.6593 ns	1.4709 ns	0.0610	256 B
ActorPath_ToSerializationFormatWithAddress	1	168.242 ns	2.5289 ns	2.1117 ns	0.0610	256 B
ActorPath_Parse	100000	281.081 ns	1.4482 ns	1.2838 ns	0.0992	416 B
ActorPath_Concat	100000	38.480 ns	0.1676 ns	0.1309 ns	0.0268	112 B
ActorPath_Equals	100000	4.377 ns	0.0479 ns	0.0425 ns	-	-
ActorPath_ToString	100000	50.507 ns	0.1441 ns	0.1203 ns	0.0268	112 B
ActorPath_ToSerializationFormat	100000	180.087 ns	0.3269 ns	0.2552 ns	0.0629	264 B
ActorPath_ToSerializationFormatWithAddress	100000	185.135 ns	3.4828 ns	3.0874 ns	0.0629	264 B
ActorPath_Parse	2147483647	300.098 ns	3.0413 ns	2.6960 ns	0.0992	416 B
ActorPath_Concat	2147483647	39.325 ns	0.8076 ns	0.7159 ns	0.0268	112 B
ActorPath_Equals	2147483647	4.360 ns	0.0337 ns	0.0315 ns	-	-
ActorPath_ToString	2147483647	51.842 ns	1.0444 ns	1.0725 ns	0.0268	112 B
ActorPath_ToSerializationFormat	2147483647	193.560 ns	2.6633 ns	2.2240 ns	0.0648	272 B
ActorPath_ToSerializationFormatWithAddress	2147483647	194.647 ns	3.9673 ns	6.1767 ns	0.0648	272 B

[Aaronontheweb]

You'll notice that the parsing and serialization overhead increase linearly with the size of the UID - this indicates to me that we're now correctly factoring it into our benchmarks whereas we were not doing this properly before.

[Aaronontheweb]

Parameterize the UID using increasing lengths - int.MaxValue is the upper limit of what the UID function will produce in v1.4:

akka.net/src/core/Akka/Actor/ActorCell.cs

Lines 321 to 329 in 680e101

	private static long NewUid()
	{
	// Note that this uid is also used as hashCode in ActorRef, so be careful
	// to not break hashing if you change the way uid is generated
	var uid = ThreadLocalRandom.Current.Next();
	while (uid == UndefinedUid)
	uid = ThreadLocalRandom.Current.Next();
	return uid;
	}

[Aaronontheweb]

Have the string we parse be produced by the absolute path of the ChildActorPath we use for the other tests, including the UID.