Follow up to GitHub deployments parity with wrangler-action

[Maximo-Guk]

A few follow up items for deployments parity from user feedback left on #325.

• Don't require GitHub token as an action input. Default its value to github.token (see actions/checkout for a great example), then let users turn features on/off using boolean inputs. This is a lot less confusing and aligns with the rest of the ecosystem.

• Accept environment name as input. Named GitHub environments can hold configurations, so migrating users might need this action's environment names to match their old ones, so that those configurations will still apply. And one repo can deploy multiple Wrangler apps, so their environment names must be configurable or else they will collide.

• Provide separate inputs to enable deployments vs. job summaries. Deployments add a lot of noise on the Conversation tab, whereas job summaries add a lot of noise on the Checks tab. Ideally users could choose how much noise they want.

[benbek]

In addition, supplying an environment name should propagate through the Deployments list on the repository. (currently I don't see anything on the Deployments list)