[BUG] [typescript-angular] Add "header" to reserved words

[JohnTraDolta]

Description

Having a property in the swagger.json called "header". This result in a client with a parameter called header, later in that function a variable with the same name is instantiated

Solution

Add header as a reserved word to enable the auto renaming functionality

[JohnTraDolta]

I can do a pr if anyone can point me in the right direction. 👍

[wing328]

@JohnTraDolta thanks for offering help to fix this. Can you please PM me via Slack when you've time?

https://join.slack.com/t/openapi-generator/shared_invite/enQtNzAyNDMyOTU0OTE1LTY5ZDBiNDI5NzI5ZjQ1Y2E5OWVjMjZkYzY1ZGM2MWQ4YWFjMzcyNDY5MGI4NjQxNDBiMTlmZTc5NjY2ZTQ5MGM