500 error on writing to an invalid retention

[MyaLongmire]

Writing data with an invaild rentention policy should result in a 4xx error that the client can understand not to retry sending the data. It's expected behavior that 5xx errors received by clients should result in the client re-transmitting the same data to avoid data loss.

This issue was raised by a customer here influxdata/telegraf/issues/9211

A very similar issue was raised here influxdata/influxdb/issues/20359

Steps to reproduce:

1. setup influxdb v1
2. curl with an invaild retention policy
   ex. curl "http://localhost:8186/write?db=telegraf&rp=invalid" -d "test value=1"

Expected behavior:
server responds with an error indicating client error, eg 4xx. such as. 406 Not Acceptable or some other error letting the user know it is an issue with what they are passing and not a server error

Actual behavior:
Server responds with 500 Internal Server Error

Environment info:

*InfluxDB version: 1.x