Use country flag in chart style for a bar chart

Question

I am creating a stacked bar chart from 2017 using the following data set

top2017 = <|"France" -> 147/10640, 
   "Brazil" -> 148/10640, 
   "Germany" -> 293/10640, 
   "Australia" -> 453/10640, 
   "Canada" -> 883/10640, 
   "United Kingdom" -> 1119/10640, 
   "United States of America" -> 6163/10640|>;

and I currently create this bar chart

with the following code

BarChart[top2017, ChartLayout -> "Stacked", ChartStyle -> "Rainbow", 
 Epilog -> 
  Inset[Framed[
    PointLegend[
     "Rainbow", {"France", "Brazil", "Germany", "Australia", "Canada",
       "United Kingdom", "USA"}, 
     LegendMarkers -> {Graphics[Rectangle[]]}], RoundingRadius -> 5], 
   Scaled[{0.8, 0.5}]], Frame -> True, ImageSize -> Scaled[0.5], 
 ChartLabels -> {"2017"}, 
 BaseStyle -> {FontWeight -> "Bold", FontSize -> 18}, 
 FrameLabel -> {{"% respondents", ""}, {"Year", "Ace Survey"}}]

and then I also create another bar chart for 2018 using

top2018 = <|{"Italy"} -> 203/15177,
            {"Netherlands"} -> 210/15177,
            {"Australia"} -> 549/15177,
            {"France"} -> 243/15177,
            {"Germany"} -> 689/15177, {"Canada"} -> 1020/15177,
            {"United Kingdom"} -> 1338/15177,
            {"United States of America"} -> 8635/15177|>;
BarChart[top2018, ChartLayout -> "Stacked", 
 ChartStyle -> "Rainbow", 
 Epilog -> 
  Inset[Framed[
    PointLegend[
     "Rainbow", {"Italy", "Netherlands", "Australia", "France", 
      "Germany", "Canada", "United Kingdom", "USA"}, 
     LegendMarkers -> {Graphics[Rectangle[]]}], RoundingRadius -> 5], 
   Scaled[{0.8, 0.5}]], Frame -> True, ImageSize -> Scaled[0.5], 
 ChartLabels -> {"2018"}, 
 BaseStyle -> {FontWeight -> "Bold", FontSize -> 18}, 
 FrameLabel -> {{"% respondents", ""}, {"Year", "Ace Survey"}}]

This gives me a chart that looks pretty similar to the one already included. Initially I was going to continue using "Rainbow" in chart style, but now that I see that I have some different countries in different years, I decided against that. I was initially going to use a set color for specific countries---say, set USA to red, France to blue, Germany to yellow etc etc and use that for every year. But then I was wondering: is there a way to use country flags in chart style? Initially I used

EntityValue[Entity["Country", "USA"], {"Entity", "Flag"}]

To manually produce the flag for each country. Then I just copied the flags produced and pasted them in flags = {}; where each flag image went into flags. When I plot the following I get an error

BarChart[top2017, ChartLayout -> "Stacked", ChartStyle -> flags, 
 Epilog -> 
  Inset[Framed[
    PointLegend[
     "Rainbow", {"France", "Brazil", "Germany", "Australia", "Canada",
       "United Kingdom", "USA"}, 
     LegendMarkers -> {Graphics[Rectangle[]]}], RoundingRadius -> 5], 
   Scaled[{0.8, 0.5}]], Frame -> True, ImageSize -> Scaled[0.5], 
 ChartLabels -> {"2018"}, 
 BaseStyle -> {FontWeight -> "Bold", FontSize -> 18}, 
 FrameLabel -> {{"% respondents", ""}, {"Year", "Ace Survey"}}]

where it says that

Value of option ChartStyle -> {flags} is not a style or group of styles.

tl;dr How would one go about using a flags/flags in chart style for a bar chart?

EDIT: For reference I got the idea to use the flags from here

https://www.wolfram.com/mathematica/new-in-10/entity-based-geocomputation/map-the-countries-of-africa-with-their-flags.html

as well as here

Getting all the countries' flags and then using them as chart labels?

but neither were exactly what I need.