Create a $this->error($error_message_html) and $this->warning($warning_message_html) method

[ftrotter]

When making a report there are frequently times when I know, as a report author, that there is a problem that the user or admin is going to need to fix.

I should be able to call a new function, $this->error($error_message_html) with the following result.

• No matter which functions in the report I call this from, the main screen of the report (on all of the various report types) should be replaced with the
• When calling $this->error($problem_text) this should stop further execution of the report. $this->warning($something) should add a warning to the UX but should allow the execution of the report to continue...
• $error_message_html and $warning_message_html which should be placed inside a bootstrap alert. The second, optional argument of both $this->error and $this->warning should be the name of the default css classes for interface colors. So 'warning' will show yellow, 'primary' will show the primary css color, etc based on: https://getbootstrap.com/docs/4.0/components/alerts/