Optimize some points

[JarosLucky]

• Removed some unnecessary local variables before loops.
• Replaced pairs with ipairs for places where the order table is not broken down.
• Localized some vectors so as not to create them different for each operation.
• Faster function variations are used to combine strings.
• A more effective solution to calculate the end position for the beam for the Widgets.
• A more effective way to indicate which panels in DTree are the last ones.
• Faster "MakeNiceName" function in the Player Editor.

[JarosLucky]

This PR

[Kefta]

Mostly a duplicate of https://github.com/Facepunch/garrysmod/pull/1573, though this PR is more expansive.

[JarosLucky]

Yes right, just i don't see this pr