[TIC-902] Add picture_url to MigrateUserParams

[itailevi98]

Background

The picture_url request parameter was missing from the library. It has now been added as an optional value.

Note: This adds a non-backwards compatible change to the MigrateUserRequest type for adding picture_url.

Example Usage

import (
	...
	"github.com/propelauth/propelauth-go/pkg/models"
)
apiKey := "API KEY"
authUrl := "AUTH URL"

client, err := propelauth.InitBaseAuth(authUrl, apiKey, nil)
if err != nil {
	panic(err)
}

EmailConfirmed := true
Enabled := true
Username := "testuser2"
FirstName := "Test"
LastName := "User"
Email := "[email protected]"
PictureUrl := "https://placekitten.com/200/300"

res, err := client.MigrateUserFromExternalSource(models.MigrateUserParams{
	EmailConfirmed: &EmailConfirmed,
	Enabled:        &Enabled,
	Username:       &Username,
	FirstName:      &FirstName,
	LastName:       &LastName,
	Email:          Email,
	PictureUrl:     &PictureUrl,
})
if err != nil {
	panic(err)
}

[mrmauer]

Lgtm!

[mrmauer]

lgtm