feat: add events api exception message - #213

There is more than one possible exceptional response. The non-201 responses are as follows:

• 403 - Unauthorized (the API key is invalid or Insights ingestion has been disabled)
• 422 - The payload could not be processed, either because it is malformed or because it is too large
• 429 - The daily quota has been exceeded

There is more than one possible exceptional response. The non-201 responses are as follows:

• 403 - Unauthorized (the API key is invalid or Insights ingestion has been disabled)
• 422 - The payload could not be processed, either because it is malformed or because it is too large
• 429 - The daily quota has been exceeded

We have all of those already, but are shared between errors api and events api.
This PR introduces separate messages for the 429 code.
events api:

• You have hit your events rate limit.

errors api (this one already existed):

• You have hit your exception rate limit.

You can take a look at all of them here.

Got it, thanks.