Fix #10506 Adding possibility to fetch legends images using Bearer token

[MV88]

Description

adding possibility to request images legend using bearer token

Please check if the PR fulfills these requirements

• The commit message follows our guidelines: https://github.com/geosolutions-it/MapStore2/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (check one with "x", remove the others)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

Issue

What is the current behavior?

Fix #10506

What is the new behavior?

now if the legend url needs to use a Bearer token it switches to a SecureImage component that fetches the token from state, so this will work only if the user is logged in (because the legends are behind a secured geoserver, and authentication is needed)
otherwise it will show legend not available

Breaking change

Does this PR introduce a breaking change? (check one with "x", remove the other)

• Yes, and I documented them in migration notes
• No

Other useful information

I also remove the line
addAuthenticationParameter(url, query);

because it was doing nothing placed there (returning a value not used)

[tdipisa]

@allyoucanmap can you please review this PR again on the light of latest changes? Can you approve?

[allyoucanmap]

@ElenaGallo please test this fix on DEV, thanks

[MV88]

@ElenaGallo
in order to really test this we should need an instance with bearer token enabled a security token.

in our case you can simply test a layer that has legend that is visible and not broken by this pr

[tdipisa]

Thank you @MV88

@ElenaGallo

in order to really test this we should need an instance with bearer token enabled a security token.

This test will be performed by me and @MV88 in a dedicated infrastructure.