parsers CHANGE clarify function names

- rename lys_parse_nodeid() to ly_parse_nodeid()
- rename lys_parse_instance_predicate() to ly_parse_instance_prediacte()
- both functions were moved into common.c

Both functions provide generic parsing functionality for different path
formats, not limited to schemas. Therefore they now have generic libyang
prefix instead of libyang schema prefix.
diff --git a/src/tree_schema_compile.c b/src/tree_schema_compile.c
index c4fa318..68c219f 100644
--- a/src/tree_schema_compile.c
+++ b/src/tree_schema_compile.c
@@ -1972,7 +1972,7 @@
         while (isspace(**predicate)) {
             ++(*predicate);
         }
-        LY_CHECK_GOTO(lys_parse_nodeid(predicate, &src_prefix, &src_prefix_len, &src, &src_len), cleanup);
+        LY_CHECK_GOTO(ly_parse_nodeid(predicate, &src_prefix, &src_prefix_len, &src, &src_len), cleanup);
         while (isspace(**predicate)) {
             ++(*predicate);
         }
@@ -2111,7 +2111,7 @@
         }
 
         while(path_key_expr != pke_end) {
-            if (lys_parse_nodeid(&path_key_expr, &dst_prefix, &dst_prefix_len, &dst, &dst_len)) {
+            if (ly_parse_nodeid(&path_key_expr, &dst_prefix, &dst_prefix_len, &dst, &dst_len)) {
                 LOGVAL(ctx->ctx, LY_VLOG_STR, ctx->path, LYVE_SYNTAX_YANG,
                        "Invalid node identifier in leafref path predicate - character %d (of %.*s).",
                        path_key_expr - start + 1, *predicate - start, start);
@@ -2217,7 +2217,7 @@
     ++(*path);
 
     /* node-identifier ([prefix:]name) */
-    LY_CHECK_RET(lys_parse_nodeid(path, prefix, prefix_len, name, name_len));
+    LY_CHECK_RET(ly_parse_nodeid(path, prefix, prefix_len, name, name_len));
 
     if ((**path == '/' && (*path)[1]) || !**path) {
         /* path continues by another token or this is the last token */
@@ -4381,7 +4381,7 @@
     /* search for the grouping definition */
     found = 0;
     id = uses_p->name;
-    LY_CHECK_RET(lys_parse_nodeid(&id, &prefix, &prefix_len, &name, &name_len), LY_EVALID);
+    LY_CHECK_RET(ly_parse_nodeid(&id, &prefix, &prefix_len, &name, &name_len), LY_EVALID);
     if (prefix) {
         mod = lys_module_find_prefix(ctx->mod_def, prefix, prefix_len);
         if (!mod) {
@@ -5580,7 +5580,7 @@
                         DEV_CHECK_CARDINALITY(d_del->dflts, 1, "default");
                         DEV_CHECK_PRESENCE(struct lysc_node_choice*, 0, dflt, "deleting", "default", d_del->dflts[0]);
                         nodeid = d_del->dflts[0];
-                        LY_CHECK_GOTO(lys_parse_nodeid(&nodeid, &prefix, &prefix_len, &name, &name_len), cleanup);
+                        LY_CHECK_GOTO(ly_parse_nodeid(&nodeid, &prefix, &prefix_len, &name, &name_len), cleanup);
                         if (prefix) {
                             /* use module prefixes from the deviation module to match the module of the default case */
                             if (!(mod = lys_module_find_prefix(ctx->mod, prefix, prefix_len))) {