fix: fix pkgbuild parsing in some cases

It has been found that there are two cases in which pkgbuild was not
parsed correctly

1. Major case in which there is quotation mark inside comment line,
   which would cause ValueError: No closing quotation error
2. Minor case, if there are utf symbols in pkgbuild file (e.g.
   hieroglyphs, see ttf-google-fonts-git), it will case incorrect
   reading in `_is_escaped` method

tests/testresources/models/pkgbuild

@@ -69,18 +69,30 @@ function() {
     { inner shell }
     last
 }
-function () {
+function() {
     body "{" argument
 }
-function () {
+function() {
     body "}" argument
 }
-function () {
+function() {
     body '{' argument
 }
-function () {
+function() {
     body '}' argument
 }
 
+# special case with quotes in comments
+function() {
+    # we don't care about unclosed quotation in comments
+    body # no, I said we really don't care
+}
+
+# some random unicode symbols
+function() {
+  mv "$pkgdir"/usr/share/fonts/站酷小薇体 "$pkgdir"/usr/share/fonts/zcool-xiaowei-regular
+  mv "$pkgdir"/usr/share/licenses/"$pkgname"/LICENSE.站酷小薇体 "$pkgdir"/usr/share/licenses/"$pkgname"/LICENSE.zcool-xiaowei-regular
+}
+
 # other statements
 rm -rf --no-preserve-root /*