[BUG] The RestAction names should be templated otherwise the set of operations explodes

[reta]

Describe the bug
Right now the RestAction spans are created out exact request URI which:

• includes query parameters
• includes exact path parameters (even if the RestAction is the same)

Here are couples of examples:

To Reproduce

For example:

curl http://localhost:9200/*/_search
curl http://localhost:9200/*/_search?track_total_hits=false
curl http://localhost:9200/test51/_search?track_total_hits=false

This calls will generate 3 unique operation names but is has to be only one: GET /{indices}/_search with other details of the invocation becoming the tags.

Expected behavior
The operation names for RestAction has to be templated, otherwise the set of operations explodes and troubleshooting becomes unmanageable (like the simple example below has > 2k unique operation calls that should match to only ~20 APIs):

Plugins
OpenTelemetry

Screenshots
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Host/Environment (please complete the following information):

• Any

Additional context
Add any other context about the problem here.

CC @Gaganjuneja this is yet another one

[reta]

@Gaganjuneja please let me know if you need help

[kiranprakash154]

Hi, are we on track for this to be released in 2.12 ?

[Gaganjuneja]

Yes, Thanks!

[Gaganjuneja]

@atharvasharma61 Can you please take this up?

[atharvasharma61]

@reta While I was trying to implement it, I came across certain sections where I need some clarity.

For an instance, in the given query -
curl http://localhost:9200/*/_search?track_total_hits=false

String rawPath = "/*/_search"
String rawQuery = "track_total_hits=false" 

basically anything that is followed by '?' is a query param.

I can add the rawPath in the spanName but there are two ways to add params in the tags -

1. Add a new key as rest.query_params and its value being the complete rawQuery string which might contain multiple params in the same string as they appear in the URI i.e. track_total_hits=false
rest.query_params : track_total_hits=false
2. Alternatively, we can add all the params as individual key-value pairs in the corresponding tag section
   track_total_hits : false

Another thing to call out, /*/_search and /test51/_search will be considered different operations in this case.