Make Alert Button Text Customizable

[mhellmeier]

For the Bootstrap Confirm dialog, it is currently possible to set the names of the Buttons (with the parameters, yesTitle, noTitle and cancelTitle):

kvision/kvision-modules/kvision-bootstrap/src/jsMain/kotlin/io/kvision/modal/Confirm.kt

Line 53 in 8f2b3c9

cancelVisible: Boolean = false, yesTitle: String = "Yes", noTitle: String = "No", cancelTitle: String = "Cancel",

Unfortunately, this is not possible with the Alert, because it is fixed to the hard-coded value "Ok":

kvision/kvision-modules/kvision-bootstrap/src/jsMain/kotlin/io/kvision/modal/Alert.kt

Line 80 in 8f2b3c9

val okButton = Button("OK", "fas fa-check", ButtonStyle.PRIMARY)

It would be great if the KVision user could customize this value.