fix(HAWNG-753): tweak size of the Route Diagram to fill the screen

[mmelko]

Red border is NOT a part of this PR :)

[github-actions]

Test Results

  8 files  ±0    8 suites  ±0   41m 52s ⏱️ +4s
 66 tests ±0   64 ✅ ±0   2 💤 ±0  0 ❌ ±0 
536 runs  ±0  508 ✅ ±0  28 💤 ±0  0 ❌ ±0 

Results for commit 07ac50b. ± Comparison against base commit 978b75d.

[hawtio-ci]

Test results

Run attempt: 2244
Detailed summary

NAME	TESTS	PASSED ✅	SKIPPED 💤	FAILED ❌	ERRORS 🚫	TIME 🕖
results-quarkus-node(18)-java(17)-firefox	67	64	3	0	0	312.364
results-quarkus-node(18)-java(21)-firefox	67	64	3	0	0	317.603
results-quarkus-node(20)-java(17)-firefox	67	64	3	0	0	314.932
results-quarkus-node(20)-java(21)-firefox	67	64	3	0	0	313.633
results-springboot-node(18)-java(17)-firefox	67	63	4	0	0	313.793
results-springboot-node(18)-java(21)-firefox	67	63	4	0	0	311.888
results-springboot-node(20)-java(17)-firefox	67	63	4	0	0	313.665
results-springboot-node(20)-java(21)-firefox	67	63	4	0	0	315.059

[tadayosi]

great!