Add back tooltip style, textsize, and textOnly functionality

[schloerke]

Fixes: #506

Leaflet.label version Leaflet/Leaflet.label#163 was used before upgrading to rstudio v2.0.0. Leaflet.label was absorbed into L.tooltip and we did not copy over the extra argument functionalities.

library(leaflet)
leaflet() %>% addTiles() %>% setView(-118.456554, 34.09, 13) %>% addMarkers(lng = -118.456554, 
  lat = 34.105, label = "Default Label", labelOptions = labelOptions(noHide = T)) %>% 
  addMarkers(lng = -118.456554, lat = 34.095, label = "Label w/o surrounding box", 
    labelOptions = labelOptions(noHide = T, textOnly = TRUE)) %>% addMarkers(lng = -118.456554, 
  lat = 34.085, label = "label w/ textsize 15px", labelOptions = labelOptions(noHide = T, 
    textsize = "15px")) %>% addMarkers(lng = -118.456554, lat = 34.075, 
  label = "Label w/ custom CSS style", labelOptions = labelOptions(noHide = T, 
    direction = "bottom", style = list(color = "red", `font-family` = "serif", 
      `font-style` = "italic", `box-shadow` = "3px 3px rgba(0,0,0,0.25)", 
      `font-size` = "12px", `border-color` = "rgba(0,0,0,0.5)")))

PR task list:

• Update NEWS