Wordpress - Gutenberg Inspector Controls

TextControl is from wp.components not wp.blocks.

const {
    registerBlockType,
    RichText,
    AlignmentToolbar,
    BlockControls,
    InspectorControls,
} = wp.blocks;
const {
    TextControl
} = wp.components;

Changing that I was able to get your block to work fine instead of error in Gutenberg 2.2.0.

InspectorControls is deprecated as of v2.4

https://github.com/WordPress/gutenberg/blob/9ebb918176c1efd0c41561d67ea3273bae5d3d6a/docs/deprecated.md#L15

wp.blocks.InspectorControls.* components removed. Please use wp.components.* components instead.

This is right at the top of your code:

const {
    registerBlockType,
    RichText,
    AlignmentToolbar,
    BlockControls,
    InspectorControls,
    TextControl
} = wp.blocks;

Specifically:

const {
    ...
    InspectorControls,
    ...
} = wp.blocks;

This is deprecated and won't work, as the deprecated doc on the Gutenberg repo says so:

wp.blocks.InspectorControls.* components removed. Please use wp.components.* components instead.