May relate to #301.

Currently many containers have some sort of OS assumption baked into their 'default' tags, and the present various other decisions (OS, libc, etc) as sub-tags related to that base tag. Take the dotnet/aspnet image for example:

you've got:

• the default debian bookworm image
• alpine
• alpine 3.17 (same alpine version, just more explicit)
• slim debian bookworm
• ubuntu jammy
• slim ubuntu jammy

It would be great if we could keep most of the inference in place but allow users to switch OS/libc/etc with a suffix switch like ContainerBaseImageTagSuffix. The logic would be

• If inferring a base image at all (meaning the user didn't provide a ContainerBaseImage)
• and the ContainerBaseImageTagSuffix is present
• ContainerBaseImage should be set to the inferred _ContainerBaseRegistry followed by the inferred _ContainerBaseImageName, with the inferred _ContainerBaseImageTag and finally the ContainerBaseImageTagSuffix:

<ContainerBaseImage Condition="'$(_ContainerIsUsingMicrosoftDefaultImages)' == 'true'">$(_ContainerBaseRegistry)/$(_ContainerBaseImageName):$(_ContainerBaseImageTag)$(ContainerBaseImageTagSuffix)</ContainerBaseImage>

This works great for the MS-supplied/inferred images, but it wouldn't work so well in the general case (when a user wants to set a base image and separately manage the tag suffix), therefore if the user isn't using our inference AND there is a ContainerBaseImage and ContainerBaseImageTagSuffix, then the two should be concat'd together.