[Change Request] Algorithm decorators

[bartvanb]

Description
In the algorithms, there are a couple of methods that we want to rename. The best is to do this in v4.0, so that we don't face compatibility issues later. Renames should include:

• ~~ The central methods should get a prefix central_ ~~
• The central method should not be named master anymore
• The local methods should get a different prefix than RPC_ as that is unclear (maybe simply local_)

Note that this list is not exhaustive:

• when implementing, consider other name changes

[bartvanb]

It might be a good idea to also accept the old prefixes (RPC_) and if someone provides a function that already includes the prefix (e.g. *central*_average) that this is detected and works without error.

[frankcorneliusmartin]

Instead of prefixes we could also consider using:

@data 
@client
@socket
def method(data, client, socker, args*, kwargs**):
    pass

Decorators register which signature belongs to which method, which then can be read by the dispactch_rpc method (

vantage6/vantage6-client/vantage6/tools/dispatch_rpc.py

Lines 63 to 64 in fa0ab4f

	result = method(client, data, *args, **kwargs) if master else \
	method(data, *args, **kwargs)

).

[bartvanb]

Note that with the above, we will be letting go of the distinction between 'master' and 'RPC' methods, so there would no longer be a need for the prefixes

[bartvanb]

• add support to use multiple databases in one run
• adapt decorator to make it suitable for using multiple databases in one algorithm run

This should be done by giving an argument to the decorator, that should somehow be fed back to the way in which the algorithm is called

[frankcorneliusmartin]

Lets test this when we create our first algorithm

[frankcorneliusmartin]

I tested this using the average:v4 algorithm the @data and @algorithm_client decorators work as expected.