Further licensing work

- Fix several inaccuracies with several files not marking Dan's
   authorship. Most of these are new files, where the code was moved from
   somewhere else:
   - In the public API:  IDynamicLuaObject, ILuaAPI, TaskCallbakc,
     IDynamicPeripheral, UpgradeBase
   - In the ROM: fs, http, require

 - Do not mark Dan as an author for entirely new code. This affects
   DetailHelpers, DropConsumer, FluidData, InventoryMethods, ItemDetails,
   MonitorRenderState, NoTermComputerScreen, Palette, PlatformHelperImpl,
   UploadFileMessage, the Terminal tests, and any speaker-related files.

 - Relicence many files under the MPL where we have permission to do
   so. See #1339 for further details.

Thank you to everyone who has contributed so far! Cannot overstate how
appreciated it is <3.

doc/stub/global.lua

@@ -1,6 +1,6 @@
 -- SPDX-FileCopyrightText: 2020 The CC: Tweaked Developers
 --
--- SPDX-License-Identifier: LicenseRef-CCPL
+-- SPDX-License-Identifier: MPL-2.0
 
 --[[-
 Functions in the global environment, defined in `bios.lua`. This does not

doc/stub/os.lua

@@ -1,8 +1,6 @@
 -- SPDX-FileCopyrightText: 2020 The CC: Tweaked Developers
 --
--- SPDX-License-Identifier: LicenseRef-CCPL
-
--- Defined in bios.lua
+-- SPDX-License-Identifier: MPL-2.0
 
 --[[- Loads the given API into the global environment.