Leverage Functions to proxy API keys

[yangwao]

We are aware that we are serverless NFT gallery, thus due security issues we need hide some secrets.

Would be nice to use https://docs.netlify.com/functions/build-with-typescript/ probably?
Seems pricing is fair https://www.netlify.com/pricing/#add-ons-functions

Don't forget to regenerate keys for

• pinata
• textile

Once done

[vikiival]

Closed by #535

[vikiival]

I made textile keys invalid

[yangwao]

I made textile keys invalid

♿️