Remove useless files

[cjcchen]

The following files should be removed from the ecosystem subfolders.

'ecosystem//.gitignore'
'ecosystem//.bazelrc'
'ecosystem//.gitattributes'
'ecosystem//.npmrc'
'ecosystem//.prettierrc'
'ecosystem//.prettierignore'
'ecosystem/**/.licenserc.yaml'

[harish876]

A few of these file are necessary for the ecosystem projects to work. That being said the necessary headers have been added to these