DX-5102: Config Split Recipe Issues

[mikemadison13]

Describe the bug
There are a number of issues with the current Config Split recipe:

1. the config splits are set to "true" by default (when they should be disabled by default). Splits should be enabled in the proper contexts by BLT or other code
2. the way the recipe generates the splits can cause CI failures, as it does not place the .htaccess file in the config directories
3. the config split recipe does not add config split / config filter as an enabled module. so, again, it can cause config import problems as it stands because it doesn't actually enable the modules. this has been resolved in the davidtrainer/blt-site-studio plugin and we should replicate that logic here.