Handle human readable number casting in general

[mathemancer]

Problem

Currently, casting from textual types (e.g., TEXT) to numbers relies on the default PostgreSQL number handling. This will be solved for the NUMERIC type once #1107 is solved, but we should also handle other number types.

Proposed solution

We should write custom logic to allow handling casting more strings to number types.

• Casting to number types with decimals should use the same (or very similar) logic to casting to NUMERIC.
• Casting to number types without decimals (e.g., INTEGER) should use a subset of that logic that handles only grouping separators.

Additional context

This was originally inspired by the custom casting work for money types. See #1137 . This issue should complete the work begun when solving #1107 .

[mathemancer]

Marking this as blocked until #1107 is solved.

[Cronus1007]

@mathemancer I would like to work upon this issue once it gets unblocked.