Add the plugin checkstyle to catch code style issues

[flyrain]

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

#1095 (comment)

Describe the solution you'd like

There are code style issue like star import. It's better to catch them with a tool.

[frHimanshu]

Hello I would like to work on this issue. May we meet in pr?

[snazy]

Hint: here's code that should integrate easily into Polaris

[nssalian]

@snazy @frHimanshu is there active work on this or can I take a stab at it?

[frHimanshu]

@snazy @frHimanshu is there active work on this or can I take a stab at it?

Go ahead

[gfakbar20]

hi @nssalian are you still working on this? if no, i will open a pr