Confluence API V2 uses string type for spaceId - Library uses int

[abetterbuilder]

Is your feature request related to a problem? Please describe.
The v2 API documentation shows the POST body requiring a string for spaceId

However, type PageCreatePayloadSchema has SpaceID int which makes it impossible to send most requests as they use strings.

Describe the solution you'd like
Change:

type PageCreatePayloadScheme struct {
	SpaceID int                           `json:"spaceId,omitempty"`
	Status    string                        `json:"status,omitempty"`
	Title       string                        `json:"title,omitempty"`
	Body     *PageBodyRepresentationScheme `json:"body,omitempty"`
}

to:

type PageCreatePayloadScheme struct {
	SpaceID string                          `json:"spaceId,omitempty"`
	Status    string                        `json:"status,omitempty"`
	Title       string                        `json:"title,omitempty"`
	Body     *PageBodyRepresentationScheme `json:"body,omitempty"`
}

[abetterbuilder]

Opened this PR to fix: #248