fix: Library couldn't be imported as ES module

[jimmycallin]

• I have added automatic tests where applicable
• The PR title is suitable as a release note
• The PR contains a description of what has been changed
• The description contains manual test instructions

Changes

Without setting type: "module", the library couldn't be imported as es module. This caused it to throw the following error when trying to import { Session } from an ES module:

SyntaxError: Named export 'Session' not found. The requested module '@ftrack/api' is a CommonJS module, which may not support all module.exports as named exports. 

By changing the name of the umd package to use cjs file ending, it is still working properly as a CJS module as well, not causing any breaking changes.

Test

Try to import it in both a CJS and ESM setting, making sure it's working as expected in both.

Example:

test.mjs:

import { Session } from "@ftrack/api"; 

test.cjs:

const { Session } = require("@ftrack/api");