AddBicepTemplateString should output a resourceName.module.bicep instead of a random path.

[mitchdenny]

Currently when we AddBicepTemplateString(...) the manifest contains a relative path to the temp directory and a random file. The filename should be predictable and published alongside the manifest file with the name <resourceName>.module.bicep to be consistent with the other resources.

@davidfowl already had a fix on another branch:

aspire/src/Aspire.Hosting.Azure/AzureBicepResource.cs

Lines 76 to 78 in e3f8ef6

	path = TempDirectory is null
	? Path.Combine(directory ?? Directory.CreateTempSubdirectory("aspire").FullName, $"{Name.ToLowerInvariant()}.bicep")
	: Path.Combine(TempDirectory, $"{Name.ToLowerInvariant()}.bicep");