=act reimplement actor path validation without regex

While working on fixing https://github.com/akka/akka/pull/16347 I decided to let go of the regexp and impl simpler methods.

I found that on a smaller scale the new methods are way better, but in the grand scheme of things there seems to be a larger trade off at higher percentiles.

I got to:

```
+[info] a.a.ActorCreationBenchmark.synchronousStarting       ss     20000       16.413        1.494       us
```

from an initial:

```
+[info] a.a.ActorCreationBenchmark.synchronousStarting       ss     20000       27.022        1.903       us
```

but the higher percentiles got hit quite hard (*averages mean nothing* mantra kicks in...).

Note: These implementations pass tests in akka actor and survive the `...|%67` which caused the regex based impl to blow up.

Do you think it is worth trying one of these impls or am I on the wrong way?
It actually is (!), because it's running on the 7k long name.
On a normal name the numbers are more "expected":

```
[info] a.a.ActorPathValidationBenchmark.handLoop7000       --- blows up
[info] a.a.ActorPathValidationBenchmark.handLoop7000       thrpt        20       30.381        0.613   ops/ms

"actor-1"
[info] a.a.ActorPathValidationBenchmark.handLoopActor_1    thrpt        20    36925.195      963.887   ops/ms
[info] a.a.ActorPathValidationBenchmark.oldActor_1         thrpt        20     1624.433       46.169   ops/ms
```