refactor(camel-plugin): polish the look and feel

[mmelko]

• Set the default background to the white color
• Set trees height to whole page
• Replace Cards with Panels across camel-plugin components and also in Attributes and Operation shared components

Some images after the change:

[github-actions]

Test Results

  8 files  ±0    8 suites  ±0   50m 24s ⏱️ -10s
 66 tests ±0   64 ✅ ±0   2 💤 ±0  0 ❌ ±0 
536 runs  ±0  508 ✅ ±0  28 💤 ±0  0 ❌ ±0 

Results for commit dae41fd. ± Comparison against base commit 4c1e92c.

[hawtio-ci]

Test results

Run attempt: 1509
Detailed summary

NAME	TESTS	PASSED ✅	SKIPPED 💤	FAILED ❌	ERRORS 🚫	TIME 🕖
results-quarkus-node(18)-java(17)-firefox	67	64	3	0	0	373.716
results-quarkus-node(18)-java(21)-firefox	67	64	3	0	0	373.551
results-quarkus-node(20)-java(17)-firefox	67	64	3	0	0	374.672
results-quarkus-node(20)-java(21)-firefox	67	64	3	0	0	376.184
results-springboot-node(18)-java(17)-firefox	67	63	4	0	0	372.364
results-springboot-node(18)-java(21)-firefox	67	63	4	0	0	387.697
results-springboot-node(20)-java(17)-firefox	67	63	4	0	0	378.875
results-springboot-node(20)-java(21)-firefox	67	63	4	0	0	387.919