convert_to_grob: Takes in an object, and converts it to a grob based on...
In grobblR: Creating Flexible, Reproducible 'PDF' Reports

Takes in an object, and converts it to a grob based on inputted aesthetics arguments.

1	convert_to_grob(x, height, width, aes_list = ga_list())

`x`	The object which needs to be converted to a grob. Must be either: A data.frame/matrix, the file name of a .png image, a character string, a vector, a ggplot object, or `NA` (for an empty grob).
`height`	The numeric height in mm of the desired grob.
`width`	The numeric width in mm of the desired grob.
`aes_list`	The list outputted by `ga_list` which contains elements to adjust aesthetics to the grob of `x`. Different type of grobs have different types of elements of this list which will affect its aesthetics. Possible elements for character strings, matrices and images can be found in `ga_list`.