Complex regex to capture digits and words containing comma and spaces

I have an input: 'BOOM', 'GRE,M', 'H SE', 1,2

Now, I want to split the string on the conditions:

1. If it a word in the string is surrounded by a single quote, remove the single quote e.g 'BOOM'==> BOOM, 'GRE,M' ==> GRE,M, 'H SE'==> H SE (the space should be kept). So, as the example shows, if the word has a space as in the "'H SE'" example, only the single quote should be removed and the space preserved.
2. if it is a word with no single quote, then do nothing e.g 1 ==>1 , 2==>2

I have a regex '(.*)', but this only takes care of words, within the single quotes. So, with the regex, I could easily get the following: BOOM, GRE,M, H SE BUT NOT the 1, and 2. What regex will do this?