feat: add Apps endpoint and query parameter support

- add `Apps` endpoint to the `Client` struct and initialize it in
`NewClient`
- implement `doWithJsonResponse` helper to handle request execution and
JSON decoding in one step
- update `newRequest` to support passing and encoding query parameters
via `net/url`
- rename `Option` to `ClientOption` for better clarity in the
`NewClient` signature
- refactor `Ping` tests to use a more structured nested layout
- remove `option.go` and `option_test.go` as part of the configuration
refactor

apps.go

@@ -0,0 +1,70 @@
+package onspring
+
+import (
+	"context"
+	"net/http"
+	"strconv"
+)
+
+const (
+	appsPath = "/apps"
+)
+
+type AppsEndpoint struct {
+	client *Client
+}
+
+type PagingRequest struct {
+	pageSize   int
+	pageNumber int
+}
+
+func (pr *PagingRequest) ToParams() map[string]string {
+	return map[string]string{
+		"pageSize":   strconv.Itoa(pr.pageNumber),
+		"pageNumber": strconv.Itoa(pr.pageSize),
+	}
+}
+
+type PagingOption func(*PagingRequest)
+
+type Page[T any] struct {
+	PageNumber   int `json:"pageNumber"`
+	PageSize     int `json:"pageSize"`
+	TotalPages   int `json:"totalPages"`
+	TotalRecords int `json:"totalRecords"`
+	Items        []T `json:"items"`
+}
+
+type App struct {
+	Href string `json:"href"`
+	Id   int    `json:"id"`
+	Name string `json:"name"`
+}
+
+func (p *AppsEndpoint) Get(ctx context.Context, pagingOpts ...PagingOption) (Page[App], error) {
+	pagingRequest := &PagingRequest{
+		pageSize:   1,
+		pageNumber: 50,
+	}
+
+	for _, opt := range pagingOpts {
+		opt(pagingRequest)
+	}
+
+	req, requestCreationErr := p.client.newRequest(ctx, http.MethodGet, appsPath, pagingRequest.ToParams(), nil)
+
+	var page Page[App]
+
+	if requestCreationErr != nil {
+		return page, requestCreationErr
+	}
+
+	responseErr := p.client.doWithJsonResponse(req, &page)
+
+	if responseErr != nil {
+		return page, responseErr
+	}
+
+	return page, nil
+}