Rename context states for DatasetManagerContext

[nozomione]

Context

We currently defined the following states for DatasetManagerContext:

• dataset : used to store the user-created dataset (i.e., My Dataset) in localStorage
• datasetId: used to store the user-created dataset ID (i.e., My Dataset's ID) in localStorage

To differentiate other datasets (e.g., shared, one-off downloads) in the codebase, we want to change these state names to explicitly indicate that they are solely used for users' "My Datasets".

Problem or idea

We should rename these states in the dataset manager context and adjust their references throughout the codebase.

Solution or next step

1. Rename theDatasetManagerContext states:

• dataset to myDataset
• datasetId to myDatasetId

2. Update these state references in the codebase to reflect these changes