Refactor data access repositories for modular pipeline change

Description

Partially resolves #1899

Create a dictionary of node and modular pipeline mapping for faster search
Add parameters set to keep track of parameters (As parameter nodes do not have modular pipelines)
Add populate_tree method which takes care of inputs/outputs and children for all the modular pipelines within a registered pipeline
Add explode_namespace method which takes care of expanding a nested namespace.
Modify add_inputs and add_outputs methods to take a Set[str] of inputs and outputs that are calculated in populate_tree method
Add add_children method which resolves the modular pipeline child nodes
Add _add_children_to_parent_pipeline method which resolves adding children to parent modular pipeline in-case of nesting
Add _add_datasets_as_children method which adds datasets as children to the modular pipeline
Update tests

This PR is part of a bigger refactor (https://github.com/kedro-org/kedro-viz/pull/1897) of modular pipelines and is created to ease review process.
The CI build might fail as this PR is not self-sufficient