Tools and options as enum values

## Current Behavior

In many cases in the frondend code we use string values instead of consistent enum values (e.g. tools)

```
<mat-icon [svgIcon]="getToolIconName('ZOOM_OUT')"></mat-icon>
```
```
[disabled]="!isToolSupportedByCurrentTag('RECTANGLE')"
````

## Expected Behavior

We should introduce and use enums with appropriate values. 