title: Query post_title OR meta_query
body: <p>I'm searching for a solution for my WordPress custom query problem.
  I have a search-form where the user can input some text, this text can be a word from the <code>post_title</code> or an <code>meta_value (Company ID)</code>.</p>
  <p>I need to search the string in <code>post_title</code> OR the <code>meta_key-Field</code> &quot;id-number&quot;,
  but I also have some other additional search params.
  These are my Args for the <code>WP_Query</code>:</p>
  <pre><code>Array(
      [post_type] =&gt; company
      [pagination] =&gt; 1
      [posts_per_page] =&gt; 10
      [paged] =&gt; 1
      [meta_query] =&gt; Array
          (
              [relation] =&gt; AND
              [0] =&gt; Array
                  (
                      [0] =&gt; Array
                          (
                              [key] =&gt; id-number
                              [value] =&gt; FOOBAR
                          )
  
                      [1] =&gt; Array
                          (
                              [key] =&gt; post_title
                              [value] =&gt; FOOBAR
                              [compare] =&gt; LIKE
                          )
  
                      [relation] =&gt; OR
                  )
  
              [1] =&gt; Array
                  (
                      [relation] =&gt; AND
                      [0] =&gt; Array
                          (
                              [0] =&gt; Array
                                  (
                                      [key] =&gt; country
                                      [value] =&gt; USA
                                  )
                              [relation] =&gt; OR
                          )
                  )
          )
  )
  </code></pre>
  <p><code>Array[meta_query][0][1] (post_title)</code> is only a placeholder - i know that can't work, but how can i search for
  <code>(id-number OR post_title)</code> AND <code>(all other vars...)</code></p>