Add additional config to docs about how to use remote browser in test

[tan-linx]

Adds additional config to docs about how to use remote browser in test (for Docker, Selenium Grid, CI, etc.). We need this config for testing the upload of files with Active Storage. Closes #43682, #47706

[viktorianer]

Hey @p8 or @vipulnsward, could you have a look at this improvement, please?

[p8]

I think it's clearer if we just use an if-statement:

Suggested change

	options = {
	browser: ENV["SELENIUM_REMOTE_URL"].blank? ? :chrome : :remote,
	url: ENV["SELENIUM_REMOTE_URL"].blank? ? nil : ENV["SELENIUM_REMOTE_URL"]
	}
	options = if ENV["SELENIUM_REMOTE_URL"].present?
	{ browser: :remote, url: ENV["SELENIUM_REMOTE_URL"] }
	else
	{ browser: :chrome }
	end

[viktorianer]

I think it's clearer if we just use an if-statement:

Good idea. What abbaut using present?? We had cases, where the url was just "" and the error message did not help to figure out this issue. I think it is safer to use blank? here.

[zzak]

I think you can also use ENV.fetch with a default instead of multiple if/else:
https://docs.ruby-lang.org/en/master/ENV.html#method-c-fetch

[viktorianer]

OK, together it would be:

url = ENV.fetch("SELENIUM_REMOTE_URL", nil)
options = if url
    { browser: :remote,  url }
  else
    { browser: :chrome } 
  end

Can we create a new PR, as @tan-linx is not responding :)?