plugins CHANGE unify naming in plugins API

All the symbols connected with type plugins are now prefixed by
lyplg_type_ and symbols connected with extensions have lyplg_ext_
prefix.
diff --git a/src/plugins_exts_nacm.c b/src/plugins_exts_nacm.c
index ed670a8..f80d145 100644
--- a/src/plugins_exts_nacm.c
+++ b/src/plugins_exts_nacm.c
@@ -67,14 +67,14 @@
     return LY_SUCCESS;
 
 emem:
-    lyext_log(arg->c_ext, LY_LLERR, LY_EMEM, NULL, "Memory allocation failed (%s()).", __func__);
+    lyplg_ext_log(arg->c_ext, LY_LLERR, LY_EMEM, NULL, "Memory allocation failed (%s()).", __func__);
     return ret;
 }
 
 /**
  * @brief Compile NAMC's extension instances.
  *
- * Implementation of lyext_clb_compile callback set as lyext_plugin::compile.
+ * Implementation of ::lyplg_ext_compile_clb callback set as lyext_plugin::compile.
  */
 static LY_ERR
 nacm_compile(struct lysc_ctx *cctx, const struct lysp_ext_instance *p_ext, struct lysc_ext_instance *c_ext)
@@ -98,7 +98,7 @@
 
     /* check that the extension is instantiated at an allowed place - data node */
     if (!LY_STMT_IS_NODE(c_ext->parent_stmt)) {
-        lyext_log(c_ext, LY_LLWRN, 0, lysc_ctx_get_path(cctx),
+        lyplg_ext_log(c_ext, LY_LLWRN, 0, lysc_ctx_get_path(cctx),
                 "Extension %s is allowed only in a data nodes, but it is placed in \"%s\" statement.",
                 p_ext->name, ly_stmt2str(c_ext->parent_stmt));
         return LY_ENOT;
@@ -109,7 +109,7 @@
             /* note LYS_AUGMENT and LYS_USES is not in the list since they are not present in the compiled tree. Instead, libyang
              * passes all their extensions to their children nodes */
 invalid_parent:
-            lyext_log(c_ext, LY_LLWRN, 0, lysc_ctx_get_path(cctx),
+            lyplg_ext_log(c_ext, LY_LLWRN, 0, lysc_ctx_get_path(cctx),
                     "Extension %s is not allowed in %s statement.", p_ext->name, lys_nodetype2str(parent->nodetype));
             return LY_ENOT;
         }
@@ -125,10 +125,10 @@
              * We check for all NACM plugins since we want to catch even the situation that there is default-deny-all
              * AND default-deny-write */
             if (parent->exts[u].def == c_ext->def) {
-                lyext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
+                lyplg_ext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
                         "Extension %s is instantiated multiple times.", p_ext->name);
             } else {
-                lyext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
+                lyplg_ext_log(c_ext, LY_LLERR, LY_EVALID, lysc_ctx_get_path(cctx),
                         "Extension nacm:default-deny-write is mixed with nacm:default-deny-all.");
             }
             return LY_EVALID;