Release v0.38.9

• 🌟 New feature: Chart (Advanced) - new JSON mode: chart a JSON datapoint holding label/value entries, no history adapter needed
• 🌟 New feature: Chart (Advanced) - JSON mode can read the label as a timestamp (epoch ms/s or ISO) and draw a real time axis
• 🌟 New feature: Chart (Advanced) - JSON mode detects the label and value fields on its own and offers the datapoint's actual keys for picking