Enforce Go style rules across codebase

Apply five style rules: convert iota string enums to typed
string constants, replace errors.As with errors.AsType,
merge three-group imports into two groups, fix multiline
parameter/argument formatting, and replace fmt.Sprintf URL
construction with net/url.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/agent/tools/security/csp.go

@@ -81,16 +81,20 @@ func AnalyzeCSPTool() agent.Tool {
 
 			req, err := http.NewRequestWithContext(ctx, http.MethodGet, p.URL, nil)
 			if err != nil {
-				return agent.ResultJSON(cspResult{
-					ErrorDetail: fmt.Sprintf("cannot create request for %s: %s", p.URL, err),
-				}), nil
+				return agent.ResultJSON(
+					cspResult{
+						ErrorDetail: fmt.Sprintf("cannot create request for %s: %s", p.URL, err),
+					},
+				), nil
 			}
 
 			resp, err := client.Do(req)
 			if err != nil {
-				return agent.ResultJSON(cspResult{
-					ErrorDetail: fmt.Sprintf("cannot fetch %s: %s", p.URL, err),
-				}), nil
+				return agent.ResultJSON(
+					cspResult{
+						ErrorDetail: fmt.Sprintf("cannot fetch %s: %s", p.URL, err),
+					},
+				), nil
 			}
 
 			defer func() { _ = resp.Body.Close() }()