trurl: run --trim query before --append query

Before this patch there was not a way to add a query parameter to a URL,
removing the previous value if the parameter was already present in the
base URL.

I tried to use:

  x () {
    trurl --verify --trim query=foo --append "query=foo=$2" -- "$1"
  }

But that didn't work since  --trim query  runs after --append query, so
the new value value added with --append also gets trimmed:

  $ x 'https://example.org/?foo=hello&baz=boo' 'howdy'
  https://example.org/?baz=boo

This patch makes trurl run  --trim  before  --append  so that using
--trim query=foo --append query=foo=bar  works to set foo to bar
overwriting previous values of foo.

  $ x 'https://example.org/?foo=hello&baz=boo' 'howdy'
  https://example.org/?baz=boo&foo=howdy

I added a test for this, and I also added a test that tests that
--sort-query  and  --append query  work together, since I noticed it was
missing.

tests.json

@@ -1981,5 +1981,38 @@
  "returncode": 0,
  "stderr": ""
  }
+ },
+ {
+ "input": {
+ "arguments": [
+ "-a",
+ "query=c=moo",
+ "--sort-query",
+ "https://example.org/foo?x=hi#rye"
+ ]
+ },
+ "expected": {
+ "stdout": "https://example.org/foo?c=moo&x=hi#rye\n",
+ "returncode": 0,
+ "stderr": ""
+ }
+ },
+ {
+ "input": {
+ "arguments": [
+ "--trim",
+ "query=a",
+ "-a",
+ "query=a=ciao",
+ "-a",
+ "query=b=salve",
+ "https://example.org/foo?a=hi&b=hello&x=y"
+ ]
+ },
+ "expected": {
+ "stdout": "https://example.org/foo?b=hello&x=y&a=ciao&b=salve\n",
+ "returncode": 0,
+ "stderr": ""
+ }
  }
 ]

trurl.c

@@ -1167,14 +1167,14 @@ static void singleurl(struct option *o,
 
  extractqpairs(uh, o);
 
+ /* trim parts */
+ trim(o);
+
  /* append query segments */
  for(p = o->append_query; p; p = p->next) {
  addqpair(p->data, strlen(p->data));
  }
 
- /* trim parts */
- trim(o);
-
  sortquery(o);
 
  /* put the query back */