unicode chars are buggy in this commit

i do not like the online merge conflict editor

`CosmicMetrics` default scale to window scale

adds bullet (U+2022) to font subset

replaces rendered text with bullets in password fields

- selection in password widgets is buggy

simplify bundles; use bevy's ButtonBundle and SpriteBundle for layout. Use CosmicCanvas(Handle<Image>) for rendering.

adds a `CosmicCanvas` component to hold the image cosmic draws to. allows easier interop between UI and Sprite widgets

Each type of widget now uses a single `CosmicEditBundle`, adding widget specific components with `.insert()` or as tuples.

fix transparent backgrounds with opaque text

refactor + move rendering fns to own file

Merged redraw and redraw_ui into a single function, in order to make placeholder and password code easier

Moved most of redraw_common into main redraw function, having type wrangling issues with the image replace function

* implement copy/paste for wasm

* ignore wasm specific "dead" code

* fix ctrl instead of command on mac

* fix character input if clipboard shortcut held

* extract undo redo to own fn and refac

* fix first edit not being undoable

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Co-authored-by: StaffEngineer <111751109+StaffEngineer@users.noreply.github.com>

Co-authored-by: StaffEngineer <111751109+StaffEngineer@users.noreply.github.com>

* implement copy/paste for wasm

* ignore wasm specific "dead" code

* fix ctrl instead of command on mac

* fix character input if clipboard shortcut held

* first draft

* refine placeholder logic

bug: inputting and deleting a char on a widget quickly (i think at cursor blink speed) hold the input visually for that blink duration.

needs testing: placeholder specific attrs

* fix conflict with #73

* update placeholder attrs

* small fixes

* fix cursor showing on empty readonly widgets

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Co-authored-by: StaffEngineer <velo.app1@gmail.com>