feat(Analysis): summable multipliable

[CBirkbeck]

Add some results about transforming summable sequences f n indexed by natural numbers , into multipliable sequeces of the form 1 + f n using complex and real logs.

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• depends on: [Merged by Bors] - feat(Analysis/NormedSpace/FunctionSeries): add eventually versions #16543
  

[github-actions]

PR summary 877d37ff15

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.Analysis.SpecialFunctions.Log.Summable (new file)	2038

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Declarations diff

+ Complex.log_of_summable
+ Complex.summable_nat_multipliable_one_add
+ Complex.tendstoUniformlyOn_tsum_nat_log_one_add
+ Real.log_of_summable
+ Real.summable_nat_multipliable_one_add
+ tendstoUniformlyOn_tsum_nat_eventually

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

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Increase in tech debt: (relative, absolute) = (1.00, 0.00)

Current number	Change	Type
224	1	bare open (scoped) Classical

Current commit 877d37ff15
Reference commit ea515836ea

You can run this locally as

./scripts/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[mathlib4-dependent-issues-bot]

This PR/issue depends on:

• [Merged by Bors] - feat(Analysis/NormedSpace/FunctionSeries): add eventually versions #16543
  By Dependent Issues (🤖). Happy coding!