FEAT Add the MultiJoiner and MultiAggJoiner

[Vincent-Maladiere]

Problem Description

As discussed in #751, we aim at clarifying Joiner and AggJoiner API by only allowing a single auxiliary table to be passed as __init__ argument. The multi-table scenario then has to be handled by a specific transformer.

Feature Description

• Both classes check that the auxiliary input is a list of dataframe.
• They iteratively fit Joiner instances.
• By default, it should add suffixes to the tables to be joined based on their position in the auxiliary table list.

Alternative Solutions

We can reproduce the MultiJoiner behavior by creating a list of Joiner and putting them into a scikit-learn Pipeline.

Additional Context

No response