Add eslint and fix eslint errors, other minor improvements

packages/common/src/Brand.ts

@@ -10,7 +10,7 @@ export type ConstructorTypeId = typeof ConstructorTypeId;
 export interface Brand<in out K extends string | symbol> {
 	readonly [BrandTypeId]: {
 		readonly [k in K]: K;
-	}
+	};
 }
 
 export declare namespace Brand {

packages/common/src/Function.ts

@@ -1,3 +1,4 @@
 export const identity = <A>(a: A): A => a;
 
+// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment -- unsafe by design
 export const unsafeCoerce: <A, B>(a: A) => B = identity as any;