Implement actions badge svgs (#28102)

replace #27187 
close #23688
The badge has two parts: label(workflow name) and message(action
status). 5 colors are provided with 7 statuses.
Color mapping:
```go
var statusColorMap = map[actions_model.Status]string{
	actions_model.StatusSuccess:   "#4c1",    // Green
	actions_model.StatusSkipped:   "#dfb317", // Yellow
	actions_model.StatusUnknown:   "#97ca00", // Light Green
	actions_model.StatusFailure:   "#e05d44", // Red
	actions_model.StatusCancelled: "#fe7d37", // Orange
	actions_model.StatusWaiting:   "#dfb317", // Yellow
	actions_model.StatusRunning:   "#dfb317", // Yellow
	actions_model.StatusBlocked:   "#dfb317", // Yellow
}
```
preview:

![1](5465cbaf-23cd-4437-9848-2738c3cb8985)

![2](ec393d26-c6e6-4d38-b72c-51f2494c5e71)

![3](3edb4fdf-1b08-4a02-ab2a-6bdd7f532fb2)

![4](8c189de2-2169-4251-b115-0e39a52f3df8)

![5](3fe22c73-c2d7-4fec-9ea4-c501a1e4e3bd)

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>
Co-authored-by: delvh <dev.lh@web.de>

modules/badge/badge.go

@@ -0,0 +1,104 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package badge
+
+import (
+	actions_model "code.gitea.io/gitea/models/actions"
+)
+
+// The Badge layout: |offset|label|message|
+// We use 10x scale to calculate more precisely
+// Then scale down to normal size in tmpl file
+
+type Label struct {
+	text  string
+	width int
+}
+
+func (l Label) Text() string {
+	return l.text
+}
+
+func (l Label) Width() int {
+	return l.width
+}
+
+func (l Label) TextLength() int {
+	return int(float64(l.width-defaultOffset) * 9.5)
+}
+
+func (l Label) X() int {
+	return l.width*5 + 10
+}
+
+type Message struct {
+	text  string
+	width int
+	x     int
+}
+
+func (m Message) Text() string {
+	return m.text
+}
+
+func (m Message) Width() int {
+	return m.width
+}
+
+func (m Message) X() int {
+	return m.x
+}
+
+func (m Message) TextLength() int {
+	return int(float64(m.width-defaultOffset) * 9.5)
+}
+
+type Badge struct {
+	Color    string
+	FontSize int
+	Label    Label
+	Message  Message
+}
+
+func (b Badge) Width() int {
+	return b.Label.width + b.Message.width
+}
+
+const (
+	defaultOffset    = 9
+	defaultFontSize  = 11
+	DefaultColor     = "#9f9f9f" // Grey
+	defaultFontWidth = 7         // approximate speculation
+)
+
+var StatusColorMap = map[actions_model.Status]string{
+	actions_model.StatusSuccess:   "#4c1",    // Green
+	actions_model.StatusSkipped:   "#dfb317", // Yellow
+	actions_model.StatusUnknown:   "#97ca00", // Light Green
+	actions_model.StatusFailure:   "#e05d44", // Red
+	actions_model.StatusCancelled: "#fe7d37", // Orange
+	actions_model.StatusWaiting:   "#dfb317", // Yellow
+	actions_model.StatusRunning:   "#dfb317", // Yellow
+	actions_model.StatusBlocked:   "#dfb317", // Yellow
+}
+
+// GenerateBadge generates badge with given template
+func GenerateBadge(label, message, color string) Badge {
+	lw := defaultFontWidth*len(label) + defaultOffset
+	mw := defaultFontWidth*len(message) + defaultOffset
+	x := lw*10 + mw*5 - 10
+	return Badge{
+		Label: Label{
+			text:  label,
+			width: lw,
+		},
+		Message: Message{
+			text:  message,
+			width: mw,
+			x:     x,
+		},
+		FontSize: defaultFontSize * 10,
+		Color:    color,
+	}
+}