[6.x] Handle linked field comboboxes when the text is long

[jaygeorge]

Description of the Problem

As noted in #14862, when linking a field/fieldset, if the fieldset group or fieldset name is particularly long, it causes overlapping issues. Here is an extreme example:

What this PR Does

• Fixes Centered text in link field select #14862
• left aligns the text inside the flexbox container—which is only noticeable when the text flows onto a second line
• Makes the field text slightly smaller so that we can see more information
• Clamps text to 2 lines, in case of excessive characters

How to Reproduce

1. Go to blueprints
2. Add a fieldset with long names