fmMap as async; fix invalid base for page-by-tpl; move non-twig options;

- `fmMap` now supports async functions
- fixes invalid (missing usage) of the collection.base option for page-by-tpl parts
- move `data`, `fmMap` and `customMerge` out of the `twig` config
- typings and small cleanups

mv AmpOptimizer to optional-peer-dep; add cleanHtmlCss options overwr…

…ites; configurable cssSizeLimit;

v-up as invalid npm release in 10

add pageTools; refactor internal promises; mv `cssFailOnSize` to options

- add pageTools for multi page url normalizing
- refactor internal promises, better async error handling
- mv `cssFailOnSize` to options
- add `fmLoad` as async frontmatter loader

add serve-static initialOpen support

refactor towards multi-page support;

AmpCreatorOptions
- removed `paths` in root
- added `pages` in root, with new `paths`
- optimized `media` paths with `srcMedia` and `distMedia` for shared-media across `pages`
- moved props from `twig` to each the `collection`
- added optional `style` for better `which-sass` filterting

Optimized `pageId` pass down and usage, now splitting up the `collections` using their `pageId` and the respective `pages.<pageId>.paths` as the htmlTask paths

mv `htmlPages` to `collections.%.pagesByTpl`, optimize collections;

align naming of mapped-file-info for fmMap; async jsonLoader

fix makeTwigHandler typing

fix gulp reexport