Change Trim Zeros to Trim Leading Zeros

[alesan99]

Fixes #7451

Quick fix, makes it clear that the new Trim Zeros option is specifically for trimming leading zeroes so users don't enable it with the expectation that it removes trailing zeroes.

Under the hood it turns the value into an integer to get rid of the leading zeros.

Checklist

• Self-review the PR after opening it to make sure the changes look good and
  self-explanatory (or properly documented)
• Add relevant issue to release milestone
• Add pr to documentation list
• Add automated tests
• Add a reverse migration if a migration is present in the PR

Testing instructions

• Go to app resources -> record formatter
• Configure a table format
• Click the gear next to a field
• The Trim Zeros option should now be called "Trim Leading Zeros"