[VsIntegration] Fix Max Entries completion option resetting to 25

[hpetriffer]

What changed

• XSUserControl.ReadControl: when loading a saved int into a NumericUpDown, the value was only accepted if Minimum <= value < Maximum; anything else fell back to Minimum. The value is now clamped to [Minimum, Maximum].
• Completion options page: the Max Entries maximum is raised from 1000 to 10000.

Why

On Tools → Options → X# → Completion, setting Max Entries to 1000 (or higher, which the control caps at 1000) showed 25 the next time the page was opened. The < Maximum check treated the maximum itself as out of range. Pressing OK then saved 25, so the setting really changed, not only the display.

The fix is in the shared base class, so it applies to every NumericUpDown on the X# options pages.

Notes for reviewers

• A higher Max Entries means more rows read from the code model DB per completion request, while the DB lock is held. The queries in XDatabase.prg stop reading once the limit is reached, so the cost only grows when there really are that many matches, for example a very short prefix in a large VO solution.
• I deliberately did not add a SQL LIMIT. Several loops drop rows after the query (StartsWith after LIKE, where _ is a wildcard; empty namespaces), so LIMIT N would silently return fewer than N matches.