Fix handling of terms inside other terms (Example: 'Ipsum' in 'Lorem Ipsum')

Problem/Motivation

We encountered a "Cannot unset offset of type array on array" error while using this module on a page that displays terms inside terms like 'Ipsum' in 'Lorem Ipsum'.

Steps to reproduce

• Using the \Drupal\glossify_node\Plugin\Filter\NodeTooltip filter plugin.
• Select the source node types you want to use titles from to link to their node page.
• Create a 'Ipsum' and a 'Lorem Ipsum' node of those types.
• Try displaying formatted text using the filter.

Proposed resolution

Fix the code of \Drupal\glossify\GlossifyBase::parseTooltipMatch()

Remaining tasks

Create a MR, review, merge the changes.

User interface changes

N/a

API changes

N/a

Data model changes

N/a