Restrict datahandle

[tmadlener]

BEGINRELEASENOTES

• Restrict the DataHandle to work only for collections that are from podio generated EDMs
• Remove unnecessary friendship with (deprecated and removed) Gaudi classes
• Bump the minimum required version of podio to 1.3

ENDRELEASENOTES

Another small part that falls out of #318. It looks like there is no usage of the DataHandle throughout the stack that is not a podio collection, so we can simply require that at compile time to simplify the implementation where we no longer have to handle other types.

Have we decided on a convention yet on how to use concepts? I have for now gone with constraining them in the template specification directly, but we could also go via the the requires route and keeping the template<typename T> part.

• Includes Move the DataHandle and MetaDataHandle into the k4FWCore namespace #317 (could be done without that if desired, but there are fewer sources for merge conflicts this way)

[tmadlener]

Looks like I was too fast. There are actual use cases where other things are put into the store this way, e.g.

• https://github.com/HEP-FCC/k4Gen/blob/156a87aac6be6ec183d6a5043296cfc9adc4052c/k4Gen/src/components/ConstPtParticleGun.h#L56-L59
• https://github.com/HEP-FCC/k4Gen/blob/156a87aac6be6ec183d6a5043296cfc9adc4052c/k4Gen/src/components/EDMToHepMCConverter.h#L27