Issue 215: Use API defaults for a simpler experience

[brunovieira97]

New setting to allow for Spring Initializr recommended defaults to be used for following configurations:

• Spring Boot version
• Language
• Packaging
• Java version

---

Setting: spring.initializr.enableSmartDefaults*
Type: boolean
Default value: false

*Based on feature request from Issue, could be changed to a more appropriate name.

---

The default values will be based on the default field from API's response, such as below:

"javaVersion": {
    "type": "single-select",
    "default": "17",
    "values": [
        {
            "id": "21",
            "name": "21"
        },
        {
            "id": "17",
            "name": "17"
        }
    ]
}

Closes #215

[brunovieira97]

I looked at my previous commits and realized they were not signed, for some reason. Had to force-push to fix that.