[typescript] change accessToken name parameter to optional

Created by: blackdev1l

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Description of the PR

fixes #2956 (closed) Iif you generate an axios API, you get a compilation error if tsconfig is set to 'strict'

because configuration.accessToken() requires name as paramater (not optional) but here in the code generated it calls configuration.accessToken() without passing any parameters.

I just made name an optional parameter. I don't know if this is the right way to solve the issue, i would like to have some feedback about this.

@TiFu (2017/07) @taxpon (2017/07) @sebastianhaas (2017/07) @kenisteward (2017/07) @Vrolijkx (2017/09) @macjohnny (2018/01) @nicokoenig (2018/09) @topce (2018/10) @akehir (2019/07)