feat(enterprise): add data sources github_enterprise_consumed_licenses and github_enterprise_license_sync_status

[vmvarela]

Description

Add two data sources for enterprise license management:

• github_enterprise_consumed_licenses — list of users consuming enterprise licenses, with details on each seat
• github_enterprise_license_sync_status — license sync status between enterprise and connected server instances

go-github v84 API

func (s *EnterpriseService) GetConsumedLicenses(ctx context.Context, enterprise string, opts *ListOptions) (*EnterpriseConsumedLicenses, *Response, error)
// GET /enterprises/{enterprise}/consumed-licenses

func (s *EnterpriseService) GetLicenseSyncStatus(ctx context.Context, enterprise string) (*EnterpriseLicenseSyncStatus, *Response, error)
// GET /enterprises/{enterprise}/license-sync-status

Structs

type EnterpriseConsumedLicenses struct {
    TotalSeatsConsumed *int
    TotalSeatsPurchased *int
    Users []*EnterpriseUserLicense
}
type EnterpriseLicenseSyncStatus struct {
    // sync job state, last_sync_at, etc.
}

Acceptance Criteria

• github_enterprise_consumed_licenses data source with enterprise_slug, pagination, computed seat counts and user list
• github_enterprise_license_sync_status data source with enterprise_slug and computed status fields
• Both registered in provider.go
• Docs for each
• Acceptance tests (can be skipped if enterprise license data not available in test env)