Add datatype for is_spent sqlite column

[vladimirfomene]

Description

During table creation, Sqlite does not throw an error when a column datatype is not defined. In addition, the datatype provided during table creation does not put a constraint on the type of data that can be put in that column. So you can easily put a string value in an integer column. Despite this, I think it is important for us to add the datatype for clarity.

Notes to the reviewers

You can read more about how Sqlite dynamic typing here

Checklists

All Submissions:

• [x] I've signed all my commits
• [x] I followed the contribution guidelines
• [x] I ran cargo fmt and cargo clippy before committing

Bugfixes:

• [ ] This pull request breaks the existing API
• [ ] I've added tests to reproduce the issue which are now passing
• [ ] I'm linking the issue being fixed by this PR