Normalize columns and values refactoring

[darkdef]

Q	A
Is bugfix?	❌
New feature?	❌
Breaks BC?	❌

[what-the-diff]

• Removed the normalization of insertColumns and updateColumns.
• Added a new parameter to upsert() method: $insertParams, which is an array containing values for INSERT statement (if any).
• Updated the code that generates SQL query string so it uses this new parameter when generating VALUES clause in INSERT part of UPSERT statement if present; otherwise, it falls back to using old behavior where column names are used as placeholders instead of actual values (which was done by previous version).