Improved type for Value

[daytonlowell]

We were switching some code in one of our apps to use one of our own wrappers for interacting with a mysql db, in doing so we got TS errors that we traced back to the usage of the object type in sql-concat.

I believe there are some gotchas with the object type in TS.

let x: object = { a: 1 }

x.a // Error Property 'a' does not exist on type 'object'.

Record<string, unknown> is a more specific type.

That being said, it would appear that both mysql2 and @types/mysql use any for the value prop, so maybe we should just do the same?