Fix trying to fetch images with zero fillWidth (#1753)

## Description
The bug report was caused by a race condition where the image URL was
built before the grid was fully laid out causing a `fillWidth=0` and the
`remember` would not reset after the `fillWidth` was updated to the
actual value. So this PR fixes the `remember`.

Furthermore, some extra guards are added to only pass the `fillWidth` &
`fillHeight` params if greater than 0.

Finally, the `EpisodeCard` code is deleted because it's height & width
logic was overly complicated and `BannerCardWithTitle` provides better
functionality anyway.

### Related issues
Should fix #1751
Maybe #1156 is also fixed by this

### Testing
Emulator, but I haven't been able to reproduce the race condition, but
the fix makes sense given the bug report

## Screenshots
N/A

## AI or LLM usage
None

app/src/main/java/com/github/damontecres/wholphin/services/ImageUrlService.kt

@@ -223,11 +223,11 @@ class ImageUrlService
                 imageType = imageType,
                 maxWidth = maxWidth,
                 maxHeight = maxHeight,
-                width = width,
-                height = height,
+                width = width?.takeIf { it > 0 },
+                height = height?.takeIf { it > 0 },
                 quality = quality,
-                fillWidth = fillWidth,
-                fillHeight = fillHeight,
+                fillWidth = fillWidth?.takeIf { it > 0 },
+                fillHeight = fillHeight?.takeIf { it > 0 },
                 tag = tag,
                 format = format,
                 percentPlayed = percentPlayed,