Refactor Reactions Datamodel

[nathankoerschner]

Refactor datamodel (in database and figma file) to include a reaction_history table as well as a reaction entity table.

Then refactor ETL accordingly.

reaction entity properties:

• userId
• messageId
• reactionAddedTimestamp

Then all other data, such as "deleted", "emoji", etc can go under the reaction_history table. This stays consistant with the rest of the datamodel.

[nathankoerschner]

Completed with this commit

[nathankoerschner]

Next need to update the database to include this new table, guild_message_reaction_histories, as outlined in the datamodel