Semantic Tokens from LSP are not recognized and not colored

Following the discussion in #274 I create this issue.

Semantic tokens received from the language server are not recognised and mapped to an appropriate colour. Therefore, the files remain black and white without any additional TextMate grammar.

By manually defining a theme that maps the LSP tokens to appropriate colours, the files will appear coloured. This should not be done by the developer of a plugin, but rather in lsp4e.

My first approach would be to map the LSP tokens to the corresponding tokens in eclipse. This way it is possible to change the colours by changing the active theme. Otherwise this would not be possible by defining static colours for a token.

Is there a list of supported token names in Eclipse?
What is the minimum set of tokens that each theme needs to define?
What other approaches might we discuss?

Start by reading discussion #274 and the LSP 3.17 semantic tokens specification linked in the issue. Trace how lsp4e receives and handles semantic tokens, then determine how Eclipse theme token mappings should be defined. Done means supported LSP tokens are recognized and colored through the active theme, with the supported token set and minimum theme requirements settled.