Make auto display results optional

[Shanrahan16]

Description of Work

Fixes #474

Testing Instructions

1. Should open browser by default.
2. Should not open browser if FitBenchmarking is run with argument --dont_open_browser
3. Should open browser if FitBenchmarking is run with argument --results_browser
4. Should not open browser if .ini file contains results_browser: no
5. Should open browser if .ini file contains results_browser: yes

Function: Does the change do what it's supposed to?

Tests: Does it pass? Is there adequate coverage for new code?

Style: Is the coding style consistent? Is anything overly confusing?

Documentation: Is there a suitable change to documentation for this change?
I will update the options table on the read the docs website once we have confirmed the names of the options

[coveralls]

Coverage decreased (-0.2%) to 85.593% when pulling 101f74b on #474_auto_display_results_option into 3fa74ab on master.

[github-actions]

Unit & System Test Results

    4 files  ±0      4 suites  ±0   7m 5s ⏱️ +6s
360 tests ±0  352 ✔️ ±0    8 💤 ±0  0 ❌ ±0 
688 runs  ±0  638 ✔️ ±0  50 💤 ±0  0 ❌ ±0 

Results for commit 6f17761. ± Comparison against base commit 64a2d1f.

♻️ This comment has been updated with latest results.