Add ability to pass in customParameters

[csidell-earny]

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• [ X ] The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
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PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ X ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Other... Please describe:

What is the current behavior?

Custom parameters are not considered, which leads to issues where you're unable to specify provider specific fields mentioned in #57

Issue Number: #57

What is the new behavior?

This takes the variable customParameters and automatically handles appending them to the authenticate call.

Does this PR introduce a breaking change?

[ ] Yes
[ X ] No

This shouldn't break anything as it only operates if the specific customParameters variable is set, and I believe most oauth strategies don't use this.

Looking for guidance if the variable name makes sense for the nest context. I didn't use customParams because I felt like that had a higher likelihood of being used by some strategy.

[Sieabah]

Any suggestions @kamilmysliwiec

[utrolig]

I'm juist chiming in here, I don't know if this is the way stuff is supposed to work, but I was able to send customParameters
by using the following code

auth.controller.ts

@UseGuards(GoogleGuard)
@Get('/google/login')
  public async loginWithGoogle(): Promise<void> {
    this._logger.debug('Redirecting user to google login.');
  }

google.guard.ts

import { Injectable, ExecutionContext } from '@nestjs/common';
import { AuthGuard } from '@nestjs/passport';

@Injectable()
class _GoogleGuard extends AuthGuard('google') {
  async canActivate(context: ExecutionContext) {
    const result = (await super.canActivate(context)) as boolean;
    const request = context.switchToHttp().getRequest();
    await super.logIn(request);
    return result;
  }
}

export const GoogleGuard = new _GoogleGuard({
  prompt: 'consent',
  accessType: 'offline',
});