Upgrade to Sequelize 7

[klondikemarlen]

Relates to:

• https://sequelize.org/docs/v7/getting-started/
• https://github.com/icefoganalytics/wrap/pull/10
• https://github.com/icefoganalytics/wrap/pull/15

Context

Is your feature request related to a problem? Please describe.
Sequelize 7 has many advantages, the main one of which is readability.
Secondary advantages are:

• managed transactions are default (cls-hooks is now part of the core).
• full featured safe SQL sanitization in raw queries
• first class TypeScript support
• nested association insert support

This will let us remove a lot of Sequelize 7 code, and make our models much smaller and easier to read.

Describe the solution you'd like
Upgrade TypeScript to latest version (5.4.5), required by Sequelize 7.
Upgrade all models to use Sequelize 7.

Describe alternatives you've considered
Keep using Sequelize 6, and/or wait until Sequelize 7 is no longer in alpha before switching. - saves time now, but will increase future workload. Sequelize 7 seems to work as well as 6.
Switch to TypeORM instead. - documentation is hard to read
Switch to Knex - complex queries are much more complicated
Switch to Rails + Active Record - I can't convince anyone that Ruby + Rails is better.