Remove !<PlatformContext> tag from UniPipe YAML instance files

[felixzieger]

When working directly with UniPipe YAML files, the tag can cause problems.

Example: https://www.terraform.io/language/functions/yamldecode does not support any tags, that are not explicitly listed on their documentation.

unipipe CLI supports !<PlatformContext>, so the workaround for this would be to transform the files via unipipe-cli before parsing them to other tools.

[JohannesRudolph]

yes I remember there was also quite a bit of hackage necessary in unipipe-cli to make it support that yaml tag... might be better to not emit them from the OSB in the first place

[DorukAkinci]

Are we sure that we don't use this parameter at all? it is strange that why we put this in the first place 😄

[JohannesRudolph]

@DorukAkinci i can't remember if this was a conscious decision or just happened as a by-product of the defaults of whatever YAML serializer the unipipe broker implementation happens to use (probably something written by spring?)

In any case, the unipipe cli would need to maintain backwards compatibility for existing repositories already using that tag. But for new services, removing that tag from the broker would be a non-breaking change.