Add tslib as runtime dependency

[MasterOdin]

This PR adds tslib as a runtime dependency for this library. When we tried to incorporate this dependency into our monorepo app, we ran into the following errors:

ERROR in /app/node_modules/echarts-for-react/lib/core.js
Module not found: Error: Can't resolve 'tslib' in '/app/node_modules/echarts-for-react/lib'
 @ /app/node_modules/echarts-for-react/lib/core.js 3:14-30

ERROR in /app/node_modules/echarts-for-react/lib/helper/is-equal.js
Module not found: Error: Can't resolve 'tslib' in '/app/node_modules/echarts-for-react/lib/helper'
 @ /app/node_modules/echarts-for-react/lib/helper/is-equal.js 4:14-30
 @ /app/node_modules/echarts-for-react/lib/core.js

The usage of tslib is due to enabling the importHelpers flag, as per its docs, the tslib dependency must be available at runtime for things to work. I'm guessing others are not hitting this error with how their package manager is hoisting the tslib dependency of echarts. In our case, it was not for whatever reason (so we have echarts/node_modules/tslib), and so no tslib could be found.