Add the TF-SDK spec and ADR-0055 to ADR-0060

This adds tf-sdk/ with the usual three-part spec, same layout as fm/, plus six ADRs for rules the existing records assume but never write down.

ADR	What it says
0055	Topology discovery gets its own interface instead of optional methods on CapabilityExecutionAdapter. Amends ADR-0027.
0056	capability_kind names what a capability is, not what you do to it. So deploy_workload is a kind and scale_workload is not.
0057	If an adapter can't execute the target SRM resolved, it raises instead of picking another one.
0058	supported_actions and supported_runtime_kinds come from TF-SDK, not from the topology declaration.
0059	SRM bootstraps its capability surface by calling discovery, not by reading a file itself.
0060	Rename the package from sunrise6g-opensdk to openop-tfsdk.

I started at 0055 because 0045, 0047, 0048 and 0053 are each used twice on different branches, so 0054 is the highest number that's safely free.

Read the three docs in order: overview, requirements, implementation. The ADRs have the reasoning behind anything the specs just state as a rule.

Nothing else changes except one line in ADR-0027's status, recording that 0055 amends it.