Extend ProcessContext with method to set executable and get feedback if available

[hohwille]

In PR #890 we had the situation that we want to execute a command via ProcessContext but only if that binary executable is actually available.
Instead of implementing such features inside one or multiple commandlets, it should belong to ProcessContext.
The idea is to add the following method to ProcessContext:

boolean setAndCheckExecutable(Path executable);

It should do the same as executable(Path executable) but additionally, it should check if that executable can really be executed.

For the implementation this code should be moved to a private method (except for the log message):

IDEasy/cli/src/main/java/com/devonfw/tools/ide/process/ProcessContextImpl.java

Lines 144 to 150 in 83acd3a

	SystemPath systemPath = this.context.getPath();
	if ((this.overriddenPath != null) || !this.extraPathEntries.isEmpty()) {
	systemPath = systemPath.withPath(this.overriddenPath, this.extraPathEntries);
	}
	String path = systemPath.toString();
	this.context.trace("Setting PATH for process execution of {} to {}", this.executable.getFileName(), path);
	this.executable = systemPath.findBinary(this.executable);

Then this method can be reused by the new setAndCheckExecutable method.
Only this way, we will also reuse the logic that is later performed to run the command (e.g. adding potential .bat or .exe or .msi extensions and more) without replicating such logic.

ATTENTION: We have some special situations where we create the ProcessContext early on and set the executable first and then other things happen (in this case installation of dependencies) and later when the run method is called, the PATH is updated and the executable can be fully resolved. Therefore the default behaviour of the existing executable(Path executable) method shall not change. Only the new method should do the additional features on top.