implement listProjects method for MapeoManager class

[achou11]

Closes #206

NOTE: Stacked on #199

Also:

• adds a $getProjectInfo to the MapeoProject class, which is used to retrieve information that's used for the resulting MapeoManager.listProjects() return value. $getProjectInfo returns the ProjectInfo type, which represents meta information about a project (different from its settings). It is currently defined as EDIT: No longer relevant

type ProjectInfo = {
  createdAt: Date
  updatedAt: Date
  projectId: string
}

[gmaclennan]

Hate to be that person, but I think this entire PR can be done in one line:

async listProjects() {
   return this.#db.select().from(projectTable).all()
}

(might actually need a little bit more).

Keeping the project table in the client instance was so that we can do this.

[gmaclennan]

All the shenanigans about having a shared index writer were so that we did not have to create project instances to get the project name, and instead we can do:

this.#db.select().from(projectTable).all()

[achou11]

addressed via b29fa8b

[achou11]

@gmaclennan ah right, forgot about the projects table 🤦‍♂️

[gmaclennan]

Mapbyr use the denullify function here?

[achou11]

addressed via 5ff8aad

[gmaclennan]

Looks good to me 👍