text: Title: [BUG] new VAR syntax with dynamic variable name throws an error if the variable comes from a lower scope 
  Body: with RFW v7.0a2
  
  I'm struggling with the new VAR syntax and the possibility to use dynamic variable names.
  
  ```robot
  *** Test Cases ***
  first
      VAR ${basename} var
      VAR ${${basename}_1} scope=GLOBAL
  
      Log ${var_1}
  ```
  
  I would assume that the test case creates a new global variable ${var_1}, but I only get the error message from robot:
  
  `[ FAIL ] Setting variable '${${basename}_1}' failed: Variable '${basename}' not found.`
  
  The same bug also occurs if I specify the scope SUITE. Without scope or with LOCAL or TEST works. 
  
  if the scope of the `${basename}` var is higher or equals the scope of the new `${${basename}_1}` it works.
  
  I would assume that the name of the dynamic variable is resolved in the same scope in which it is written, not in the scope in which it is to be defined.