Add secrets for common API keys/tokens

I have included an updated gl-sast-report.json, however it does not include the keys that were not found. Not sure how you want to handle that.

The following keys have been added.

• Google API Key
• RSA Private Key
• Google OAuth ID
• General Private Key
• Amazon AWS Access Key ID
• Twitter Access Token
• EC Private Key
• Facebook Access Token
• PGP Private Key
• MailGun API Key
• MailChimp API Key
• Stripe Standard API Key
• Twilio API Key
• Square Access Token
• Square OAuth Secret
• Amazon MWS Auth Token
• Braintree Access Token
• Picatic API Key (now eventbrite)

Here's the list the secrets analyzer was unable to find:

• Google API Key
• Google OAuth ID
• Twitter Access Token
• Facebook Access Token
• MailGun API Key
• MailChimp API Key
• Square Access Token
• Square OAuth Secret
• Amazon MWS Auth Token
• Braintree Access Token
• Picatic API Key (now eventbrite)

I also added a few more common ones: slack token, various types of google service account keys/files, and variations of pgp/ssh keys. It looks like the analyzer found all of them (except the previous list's Google API Key, Google OAuth ID)

/CC @tmccaslin who this should be assigned to?