Rename all __sveltets_* ambient declarations to __sveltets_1_* . This way, we avoid the situation where multiple ambient versions of svelte2tsx are loaded and their declarations conflict each other. #1059 for an example bug that stems from it.

The other breaking change is that svelte2tsx no longer provides a default export, svelte2tsx now is a named export. This opens up the possibility to export other utility functions alongside it.

Also added ambient types source to specify where to load the types from. This is needed in case someone has svelte-check and svelte2tsx in the same node_modules. We need to make sure svelte-check loads the types from itself, not from svelte2tsx.

Also turn off the annoying max length eslint rule - this is handled by Prettier already