Type flags WPO, HID and IDX

[joente]

Description

With the new type caching, we would required yet another boolean for the new_type() and set_type() functions.
This pull requests replaces the boolean arguments with a singe flags argument and introduces flags:

Flag	Description
WPO (2)	When set, the new type will be created with wrap-only mode enabled.
HID (4)	When set, the new type will be created with hide-id enabled. See "hid" action on mod_type for more information.
IDX (8)	When set, auto-index will be enabled for the new type. See "idx" action on mod_type for more information.

This is not a breaking change as we kept the old syntax working.

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

• Test type

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• New and existing unit tests pass locally with my changes

[joente]

• Additional fix for garbage collection. Set next thing ID after loading things from full storage gc.
• Added WPO, HID and IDX flags for new_type() and set_type() with compatibility for old syntax.
• Small improvements to type cache.