[column view] Decrease default column size to 120

[hanaral]

Problem

As it stands, in column view each column takes up so much space that files can hardly keep 2.5 of them in view at a relatively standard window size:

Combined with the autoscrolling, users have to constantly readjust the column size and scroll.

Proposal

Reducing the default column width to 120 would mostly alleviate the problem, as it keeps plenty of content on screen, while also fulfilling the purpose of it being a navigation-focused mode rather than something like icon grid mode. The length of text problem (if it is even a problem) could be solved both by implementing something like #1590 and also #1601

Prior Art