Added support for non-string parameter value

Added support for non-string parameters values (numeric, boolean) to address comment https://github.com/ylefebvre/vip-scanner/commit/d4fdbeb48fdb721edaa0778d3434a52371da3ddc#commitcomment-8323043
Added message level information to display error in blocker, warning or note sections

Created array instead of single message variable to associate with problematic parameters to include error level in addition to message. Modified add_error call to use additional information. Renamed variable in foreach loop to be more representative of its contents.

Addressing comment https://github.com/ylefebvre/vip-scanner/commit/d4fdbeb48fdb721edaa0778d3434a52371da3ddc#commitcomment-8323040
Added support to indicate position of parameter to be checked

Modified parameter array to contain all data for each parameter in an array. Split each array into separate lines to improve readability. Added element to indicate parameter position (starting at 0). Added variable to prepare RegEx pattern to find a specific number of parameters before the target parameter. Conditionally add previous parameter pattern in main search pattern if parameter position value is higher than 0.

Addresses comment https://github.com/ylefebvre/vip-scanner/commit/d4fdbeb48fdb721edaa0778d3434a52371da3ddc#commitcomment-8323018
Changed parameter info array element name from pos to position for readability
Enhanced logic to build previous_params pattern

When a position is specified for parameter and is higher than 0, build one pattern to match a set number of previous parameters. When position is not set, accept anything before target parameter.

This new logic is also easier to read than previous binary if operator.
Change slug in add_error call to use parameter value

Having the parameter value as the slug facilitates unit tests
Adjusted pattern match to avoid a parameter like livefyre3 being flagged thinking it was livefyre3

When I modified the code to accept parameters without quotes, I had missed the fact that the pattern would match when livefyre3 was used. Modified pattern to  specifically look for single quote, double quote, comma or space after parameter.
Added unit tests for new VIPParametersCheck class
Moved check logic to new method to be able to write more thorough unit tests

Many of the checks introduced in the VIP parameters check could not be exercised since the only checks in place so far were for the first parameter of a single parameter function. By moving the checking logic to a separate method that received the file path, file contents and list of checks as arguments, more thorough unit tests can be written.
Augmented and updated test suite for VIPParametersCheck class

Added multiple tests to exercise all of the checking capabilities of VIPParametersCheck class.

Renamed one test to have clearer name.