imageio: lower default jpeg quality to 95 and minimum to 5

Quality 95 offers a better default quality to size ratio.

Also, defaulting to 97, makes the slider behave slightly oddly
with a step size of 5, since it will "snap" to 92,88,... instead of
95,90,85,...

Alternatively a minimum of 1 causes the slider to snap to 1,6,11,...
instead of 5,10,15...
imageio: lower default j2k/jpeg2000 quality to 95 and minimum to 5

Quality 95 offers a better default quality to size ratio.

Also, defaulting to 97, makes the slider behave slightly oddly
with a step size of 5, since it will "snap" to 92,88,... instead of
95,90,85,...

Alternatively a minimum of 1 causes the slider to snap to 1,6,11,...
instead of 5,10,15...
imageio: lower default WebP quality to 95 and minimum to 5

Also, defaulting to 97, makes the slider behave slightly oddly
with a step size of 5, since it will "snap" to 92,88,... instead of
95,90,85,...

Alternatively a minimum of 1 causes the slider to snap to 1,6,11,...
instead of 5,10,15...