[FEA] Backstick support in DataFrame.query() method

**Is your feature request related to a problem? Please describe.**
Hi,

While trying to use the `DataFrame.query()` with columns whose name is a string with blank spaces, I have noticed that I didn't know how to do that with RAPIDS nor Pandas.

Example below:
```
df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2), 'C C': range(10, 5, -1)})
df.query('B == `C C`')
```

I have gone to Pandas doc, and I have found they support the use of backstick from version 0.25.1. Backstick has been deprecated in Python 3, but it has been introduced in Pandas to accomplish the scenario above.

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.query.html

**Describe the solution you'd like**
I'd like to have 'backstick' support in .query method in cudf.

**Describe alternatives you've considered**
As a workaround:
`df[df.B == df['C C']]`

**Additional context**
Not a stopper at all. I have just thought it might be handy to have backstick support in RAPIDS cuDF.