XFA - Fix text positions (bug 1718741)

- font line height is taken into account by acrobat when it isn't with masterpdfeditor: I extracted a font from a pdf, modified some ascent/descent properties thanks to ttx and the reinjected the font in the pdf: only Acrobat is taken it into account. So in this patch, line heights for some substituted fonts are added.
  - it seems that Acrobat is using a line height of 1.2 when the line height in the font is not enough (it's the only way I found to fix correctly bug 1718741).
   - don't use flex in wrapper container (which was causing an horizontal overflow in the above bug).
   - consequently, the above fixes introduced a lot of small regressions, so in order to see real improvements on reftests, I fixed the regressions in this patch:
     - replace margin by padding in some case where padding is a part of a container dimensions;
     - remove some flex display: some containers are wrongly sized when rendered;
     - set letter-spacing to 0.01px: it helps to be sure that text is not broken because of not enough width in Firefox.

src/core/myriadpro_factors.js

@@ -77,6 +77,7 @@ const MyriadProBoldFactors = [
   0.97579, 0.97579, 0.97579, 0.9332, 1.05993, 0.94039, 0.94039, 0.94039,
   0.94039, 0.99793, 0.94039, 0.938, 0.938, 0.938, 0.938, 0.99793, 0.95776,
 ];
+const MyriadProBoldLineHeight = 1.2;
 
 // Factors to rescale LiberationSans-BoldItalic.ttf to have the same
 // metrics as MyriadPro-BoldIt.otf.
@@ -143,6 +144,7 @@ const MyriadProBoldItalicFactors = [
   0.89544, 1.0051, 0.89364, 0.89364, 0.89364, 0.89364, 0.97276, 0.89364, 0.9,
   0.9, 0.9, 0.9, 0.97276, 0.86842,
 ];
+const MyriadProBoldItalicLineHeight = 1.2;
 
 // Factors to rescale LiberationSans-Italic.ttf to have the same
 // metrics as MyriadPro-It.otf.
@@ -208,6 +210,7 @@ const MyriadProItalicFactors = [
   0.979, 0.979, 0.979, 0.979, 0.882, 0.93559, 0.882, 0.882, 0.882, 0.882,
   0.88465, 0.882, 0.83, 0.83, 0.83, 0.83, 0.88465, 0.84596,
 ];
+const MyriadProItalicLineHeight = 1.2;
 
 // Factors to rescale LiberationSans-Regular.ttf to have the same
 // metrics as MyriadPro-Regular.otf.
@@ -273,10 +276,15 @@ const MyriadProRegularFactors = [
   1.01915, 0.926, 0.96705, 0.942, 0.942, 0.942, 0.942, 0.92241, 0.942, 0.856,
   0.856, 0.856, 0.856, 0.92241, 0.92761,
 ];
+const MyriadProRegularLineHeight = 1.2;
 
 export {
   MyriadProBoldFactors,
   MyriadProBoldItalicFactors,
+  MyriadProBoldItalicLineHeight,
+  MyriadProBoldLineHeight,
   MyriadProItalicFactors,
+  MyriadProItalicLineHeight,
   MyriadProRegularFactors,
+  MyriadProRegularLineHeight,
 };