Use smaller Vitess image to copy binaries

Current the vitess docker image we build uses the following docker image to copy some necessary vitess related binaries. This `vitess/base` image is huge (6.1GB). We want to avoid downloading this image.

FROM vitess/base:v8.0.0 AS base

However, the final vitess docker image we built is small (~1G) because it's based on another much smaller vitess docker image 

FROM vitess/lite:v8.0.0

The Vitess community will create a few smaller images (`vitess/vtctl` and `vitess/mysqlctl`). Please follow the discussion [here|https://vitess.slack.com/archives/C0PQY0PTK/p1612339740175400]. When it's done, we should start copying the binaries from those smallest images. 

Affected Dockerfiles:

• https://github.com/debezium/debezium-examples/blob/2dd6e24220706b9a0f67a0c9e64453a93259d2f8/tutorial/debezium-vitess-init/Dockerfile
• https://github.com/debezium/debezium-connector-vitess/blob/master/src/test/docker/Dockerfile