Add include to tsconfig.json to enforce strict rules and improve IDE typescript features

[tephenavies]

Our current typescript config doesn't enforce the terriajs typescript rules. It extends from terriajs config but doesn't apply the config to the files in TerriaMap: https://github.com/TerriaJS/TerriaMap/blob/893d9ffcc55c9ed863a2ed44be23e40a02e72323/tsconfig.json#L1-L3

Add an include to the tsconfig such as:

include: [
    "./lib/**/*"
]

fix any type errors that show up from changing that.